motor failed within weeks
928696
Worked well for a while, then the motor broke.  It's pretty easy to clean, although it could be easier.  Got a full refund, because the motor failed within the 30 day window.
222029
I bought this in February and the motor just died on my while making peanut butter. Not overheated or anything, just plain died.
3358587
Only worked for about 2 weeks.  The motor just quit. I sent it back - you get what you pay for.
236276
Broke in under 2 months, pretty unimpressed. Motor died
3611439
Worked awesome for 2 weeks, then the motor began making loud noises. Ordered a replacement and the same thing happened! I guess it is just not well made.
4182083
Would not buy again. After one week the motor just stopped. I called air care and they replaced it. After a month it stopped working again, I called and they replaced it. Even thou they were great on replacing it, clearly there was s a design defect somewhere
3525744
I loved using my DC 40, until after owning it for only 7 weeks, it began to make strange noises and wouldn't pivot. Now, it's in for repairs and I will be without a vacuum for the next 3 weeks. This is not the performance I expected for such an expensive product. In hindsight, I would have purcahsed a vacuum from a different company.
3835501
Well, I ran this fan 24/7 for approximately 45 days and the motor gave out.  I was hoping to get a good 6 months out of it, but alas, I will be buying a more expensive model for a replacement.
2203962
The fan worked for 3 weeks then started  to make some noise. A pulsing noise (1 per rotation) at all the speeds. You will not be able to sleep with this noise in the room and will have to replace the motor or fix it if you find the problem. It doesn't seem to be mechanical. I contacted the vendor about the issue and said there was nothing he could do for me. This is obviously a defect in the motor and the vendor was not cooperating. I do not recommend this product.
911470
Fantastic when it worked, which was about 2 weeks. Then the motor stopped initializing for no apparent reason. Couldn't for the life of me figure out how to update the firmware. Instructions sparse.
2192585
The connection piece on the motor itself is poorly made. The motor wouldn't work because of a manufacturer flaw. The electrical connector wasn't making contact to the motor body. When unplugging the wire from the harness to check it with a voltmeter, the flimsy piece completely broke off. Back to square one.
949267
Unfortunately one of the more unreliable motors I have purchased.  If you buy it, spend a little extra and pick up the extended warranty.
376533
The pump failed within a few weeks and I was left with a fancy fan.
3815632
Like another review here, It worked great for a very short time.  It ran great, moved a massive amount of air and while a little noisy, you have to remember how much flow you have going.  Unfortunately, I came home from work today and nothing.  I crawled up there and the motor is dead.  I had it set to 135 or so and we've been over 100 for days so it's seen some heat lately but I would expect it to last more than a couple weeks.  I believe it ran for about 2 weeks cycling during the days.

I guess I'll try another brand and crawl up there at 6am to see what I can do before it's too hot to work.  On the other hand... If you are questioning if it's worth installing one, the answer is overwhelmingly yes.  This makes a noticeable difference in the areas near it especially even through the proper insulation so it's definitely helping with AC costs.
2507408
Well, this looked like a good unit and the reviews were good, but I am now sorry I bought the vacuum.  I have owned it for less than one month and the motor has an problem already.  It is cycling and drawing alot of current(I know because my lights dim when using it).  It did not do that for the first 3-4 times of use.  I have checked the filters and put in a new bag and verified that there is no clog in the hoseline.  If I can find the warranty card and can get it serviced under warranty, I will report back, but this was very disappointing. Update: I brought the unit to an authorized repair center(closest was ~50-60 miles away) on 6/24.  Within a few days it was determined that the motor had failed.  Panasonic did not get the replacement motor to the repair center until 7/24 and I picked up the unit yesterday, 7/31(the tech forgot to enter that the work was done, so that was an extra few days delay.  So the pro was that it was easy to arrange for the warranty service, but the amount of time it took was fairly long.  The unit does seem to work better than when first purchased, so it was probably defective from the start.
2121717
The XV-21 was great - but I now realise (based on experience and research) it is defective and its breakdown is inevitable.  After 2 months our machine displayed a "clear the brush" error.  There was nothing stuck in the brush - rather, the brush belt was jammed.  On opening the motor casing, it was determined that the motor had stripped a section of teeth from the rubber belt and the motor housing was jammed with disintegrated rubber. I removed the rubber and freed the belt.  But subsequently, the electronics stopped working.  I contacted Neato - but they refused to repair because I had opened the motor casing - which I had only done to fix the brush belt and because the cost of returning to the US was prohibitive (we don't live in the US).  I cannot understand Neato's refusal to repair in circumstances where opening the motor casing did not cause or contribute to either problem.  Neato's only suggestion being that I buy another machine at full cost.
2510180
Thought this was a winner until I used it a half dozen times.  The suction became intermittent and then quit completely.
The motor is fine, the pump gave out (bypass valve failed).  Called customer service and they sent a repair kit at no cost, of course I had to install it myself.  Tested OK but after a couple of uses popped and then quit again.  Also the supplied hose is huge in diameter and hard to use.  Discarded it in the trash right away and used a regular size hose.  Now the rest of it is going into the trash as well.  Spend a little more and buy something that will last a while.