After firmware update very nice router
584721
If you get the latest version 5, then be sure to update to the latest firmware 1.00.4 (previous versions were buggy and caused slow downs). This is my second Linksys router and I am very pleased with its performance for Wireless G and wired. While some here are complaining that the new version doesn't run on Linux, this isn't an issue unless you plan to run third party firmware. The router is very good, especially at this low price point.
3530137
I've got a 10.0.0.x LAN inside a (SonicWALL) firewall, and I run Small Business Server 2011.
One of my three 6+ year old Netgear WiFi Access Points died, so after doing some research I selected the R6250 as a replacement, and ordered three.
The user interface on the R6250 is geared for typical (simple) home configurations, so it took me a bit of hunting around, but I finally found the Advanced > Advanced Setup > Wireless AP page.
Here, you check the "Enable AP Mode", then check "Enable fixed IP setting on this device (not recommended)", and you're able to enter the static IP, the IP subnet mask, the Gateway IP, and the DNS IP.
Now the R6250 is a straightforward Wi-Fi Access Point -- and my SBS 2011 server continues to provide DHCP and DNS services.
Another improvement in the Netgear software is the ease of upgrading the Router software.
When I first connected, there was a highlighted yellow link that prompted me to update the software.
The update downloaded and installed in less than 2 minutes.
Range and reliability so far (day 2) are great.
2206421
replaced my tired, old router. Now able to run multiple devices without lag/buffering issues
790338
My background: Software developer that uses computers almost all day long. I have business class Verizon FiOS and 5 static IPs.

Here's my experience & thoughts with this router:

* Setup was pretty easy. However, there was some browser quirkiness. If you have trouble then I suggest trying a different browser.
* In case you need it, the factory default username/password is admin/admin and the default IP is 192.168.1.1.
* I went to Administration->Firmware Upgrade and the router checked for an update, found one, and installed it. Pretty painless.
* Access the router's web interface via HTTPS is possible, but will give you a certificate error that you will have to allow/override.
* The web interface is pretty easy to use. I like it.
* I set up 2 guest networks, one on 2.4GHz, and one on 5GHz. Very easy and so far working great. It allows up to 3 guest networks on each band.
* The traffic monitor is very nice, and shows different graphs for 2.4GHz and 5GHz wireless traffic.
* I highly recommend you leave remote (WAN) access disabled. You'll potentially be opening up your router to hackers and security vulnerabilities.
* I am not using AiCloud or USB features and I'd be careful with those. I'm not sure I trust the security on features such as these.
* Under Network Map->System Status->Status it shows nice CPU and RAM usage graphs. Currently mine is showing only 45MB used and 205MB free. I think this router has 256MB of RAM. It's also showing low CPU usage (by the way, it's a dual-core ARMv7 CPU).
* The system log indicates it runs Linux 2.6.36 and has 128MB of AMD NAND flash and 255484k of available memory.
* I purchased the router at the end of September 2014 and my hardware revision is "A2".

Should anything change then I'll upgrade this review. So far I really like this router so 5 stars.

UPDATE 2014-11-24: So far it has been rock solid. I set it up and I haven't had to reset or reboot it since.

UPDATE 2016-01-05: Still extremely pleased. This is what a router should be. Set it & forget it. It just works.
24225
Initially I could not connet this device at all even upgraded firmware & server software. Spent 2/3 hours on tech support with all experiments like disabling firewalls, rebooting MP 101. But finally I found out that I needed to change my router setting from G-Only to Mixed mode (I have Linksys-G router) and got connected instantly.

Great performance, nice audio clarity, easy user interface.
7016
I bought mine from a local retailer 3 months ago and initially had issues with it for a while until a Linksys representative got in touch with me regarding a fix.  I originally had constant dropped signals (signal would just disappear and none of my tablets or laptops would see a signal) and lots of issues using my hard-drive that was connected to the router (for an example, it would literally take 3 entire minutes just to preview 20 photo thumbnails in the folders and take 90 minutes to transfer 1.5GB of data when it only took my old router 20 minutes to complete).  The fix they proposed is seen in the comment section they provided below; suggesting that the default "auto" value be changed to some constant value. In addition, I also did it for the 5GHz band and my router works flawlessly now.  It used to take FOREVER to view thumbnails on the hard-drive that's connected to the router and after changing those values, the thumbnails pop up instantly! This makes me very happy because all of my computers talk to this hard-drive and I need it to do work. I'm also no longer having buffering issues when watching Netflix or YouTube after changing those values.
4945896
There was one small issue that was handled well by customer service. The device that arrived needed it's firmware updated in order to work. The set up took me 15 minutes but then 2 hours later it crashed. Everything I knew to do wasn't working so I called customer service at Linksys. The woman I spoke to was well informed and helped me reinstate my device. Since then it is working extremely well. My Wifi is once again secure.
680439
After checking out the reviews of this router (refurbished or not) I knew I could return it. After a firmware update, it has worked awesome. No regrets. I have also purchased a 4TB WD External drive and connected it to the back of the router using the USB 3.0 connection in the back and started loading my favorite movies. No hiccups yet, keep the fingers crossed.
4232913
This router was very easy to install and get working, but after a week or so we could not connect to the wireless network anymore.  A reset of the router solved the problem, but I figured I should update the firmware just to make sure that I was up to date.  Lo and behold - the "check for firmware updates" button in the web interface of the router did not work, and it took me forever to find the belkin web page that has the latest firmware version for this router.  It's at the page below:

[...]

After I upgraded to the latest firmware version, the "check for firmware updates" button in the web interface now works ;-/.  Hey, they fixed something.  That's a good sign.
3867099
I've seen lots of complaints, but I have had no issues.  I used to be a network engineer so I might not be the best to gauge ease of configuration.  I thought it was relatively straight forward, although cluttered, and haven't had a single network issue with the router itself.  I just updated the firmware for the first time after having it for a year, so it was fairly solid out of the box.
4385460
Let me say that first and foremost this is an EXCELLENT router, but the firmware is CRAP, and updates do not help 5ghz radio issues. If you buy this router i strongly suggest flashing ASUSWRT-MERLIN. or OPENWRT. it solves 5ghz radio dropping and allows a few other bug fixes and custom tweaks. before flashing custom firmware i had to factory reset once a week to get the 5ghz band to work. this router is beast when it's tunes properly, i have 2 of these bridged and a couple of repeaters scattered around my garage and basement. We have 4 tablets, 2 Desktops, 2 Laptops, multiple Rokus and Android Boxes, and coupled with my 100mb/s internet the 3 kids and my Wife and I can stream at the same time with zero bandwidth or latency problems
3860913
I own the Netgear R6300 for 5 weeks now and I'm very satisfied so far. Anyway, after the firmware upgrade to 1.0.2.26 the router has problems with my wireless D-Link DCS-942L IP cam and my ver. 1 Roku. Sometimes they are connected and then disconnected...??? All my other wireless gadgets working fine with the R6300 (Roku 2; AppleTV; Oppo Blu-Ray DBP-93; iPad; HTC Evo 3d) so my only complaint is about the IP cam and the "old" Roku, both were working perfect with the R6300 BEFORE the firmware update.

Update 9/11/2012: together with Netgear support we figured out that since the last firmware update there is a bug on "Auto Channel" on the R6300's 2.4GHz settings, I switched from "Auto" to a fixed channel "1" and now everything works as expected again.
2967935
Working great as long as I install the latest firmware version.  I'm getting over 300 Mbps on a 12+ mile link.
4659112
Yes I've had to upgrade the firmware over the last 2 years.  But FINALLY I am receiving newly manufactured RV320's with the newest firmware already installed.  With the new firmware I have had ZERO issues in many customer's offices.
2946399
not use to these newer routers,  it pretty much does a lot of the networking for you. I haven't had to turn it off (to fix it) since I started using it.  It did stop working to force me to run a firmware update.  I personal don't think a router should be able to do that.
408463
I am very happy with this router. It seems to work really well. I initially had a hard time seeing it up but soon realized it was my mistake not the router.

The instructions are clear and big enough to read ( unlike most instructions nowadays!)

The only reason i gave 4 star instead of 5 is because the speed seems to slow down after time. It has to be reset every week or so to get the speed back to normal. But that is pretty easy as it is just pushing one button.
1016003
After reading all of the negative reviews about the early firmware I was a bit hesitant to purchase and was looking at the N56U as a cheaper, more battle-tested alternative.  My current D-Link gaming router was nearly $200 back in the day (2007) but has quickly become outdated with modern WiFi standards (mainly security).  I decided to order the N66U and received it very quickly from Amazon.  It shipped with Firmware Version 3.0.0.3.90 which is newer than the version giving people trouble.  I did notice there is now an even newer version than that available but I haven't upgraded yet.

The router is beautiful.  It runs cool, is easy to setup and has exceeded my expectations.  I have 2 HTPC's in the house, one behind a concrete wall.  My old router could barely stream SD movies to it without disruption and drops.  Since I installed the N66U as the backbone of my home network, I have been able to stream 1080p MKV's with DTS through my concrete wall without a single hiccup!  I was floored.  Really surprised me.  It has been up and running for three weeks without rebooting or needing further configuration.

Here's a list of connected devices:
Gaming desktop PC
File server PC
Living room HTPC
Bedroom HTPC
2 LAN printer/scanners
Cisco VOIP office phone
Wii
iPad
2 iPhone's
AppleTV Gen 2
DirecTV whole home DVR's

All devices were easy to setup with WPA2.  I love having the 5GHz band for HTPC's and iPad and the 2.4GHz band for the others.  Also dedicated Guest network that keeps guests off my LAN but provides access to the internet.  So many advanced features as well, too many to describe here.  An excellent value.  Kudos Asus!