Not working at first but....
937505
after I contacted the company and got some feedback I realized I had an HDMI cable, which did not come from the company, that did not work. With the new HDMI cable, that was free with the purchase from this company, everything is running through the HDMI switch as expected.

Company service: A
Quality of purchased HMDI cable and switch: A
3457891
UPDATE:

After an initial problem the seller offered a replacement device.  The new version has so far worked perfectly.  Upgraded review to 4 stars to reflect the operation of the new product and the high quality customer service.
427769
Out of the box it connected for about a minute, then stopped working. Batteries are new, so that's not the problem. Tried resyncing it, that didn't help and now the laptop won't even see it. Needless to say, this will be going back.

UPDATE: After messing with it more, I finally got it to connect and stay connected. It should not have been this difficult. I'll update again if it fails again.
1956997
It is working well so far. My first one must have been faulty. I really appreciate your good response to my problem.
4407148
Weird was the first thing I could think of when I got this to work.  It seem to have been damage during shipping or something but I had to solder a connecting point back.  However, the other weird thing was that you had to connect a certain way before it would start working.  Might have been that it was damage but I got it working at least for now.
2127848
The first unit was DOA. They were very helpful and a replacement was sent. Now all works normal. A few setup hints were missing in that how to sync the device that they provided after the problem.
2072847
works very well - once i spent some time figuring out why it was not working!!
ended up reading the reviews here and realized that the DVI part was not completely flush with the port on the monitor and so signals were not going through!! once i got that part taken care of,things are working, the monitor is working and i am happy to see it!!
4511869
Our unit quit working after only a couple months and we are past the return time period.  Now I'm going to try and go through the manufacturer to see about getting a refund of getting it replaced with one that works.  This should be fun.....
3280344
I followed the instructions and it didn't work at first. Then I e-mailed the seller. They gave me some tips and now it works perfectly. More than worth the price.
541783
I didn't need it for the first few months but the first time I eventually plugged it in, I realized it didn't work, and it was too late for a refund/replacement. I might have just gotten a defective one, but make just make sure you try it as soon as you get it.
3737905
First one was DOA, started the return/replacement process, we'll see if the second is any better. Depending on IF it works, I'll definitely update my review.
1550509
Started off bad with a red light but after about 30 mins of messing around with it, it finally worked.
2202949
The first one I tried did not work even after trying everything I was told to do. The second one went in and started working just fine. So far so good with it. Don't know yet if I will try again.
2092177
**UPDATED**
I was promptly contacted by customer service after posting my review and sent a new product. So far so good with the new one! I'll update with any issues in the future, but for now I am satisfied with the product and very happy with the customer service.

Doesn't work. Read and followed the instructions. Maybe it's just a defective one? I'll be contacting the manufacturer because it's one day past the return period. :( If I get a new one that lasts longer than a month, I'll update my review.
3430999
The first unit didn't work!  It took a circuit of return and replace but they handled it professionally, paid for my return shipping, and the new unit is as advertised.  S--- happens, so no problem.
2994906
Thought at first "oh no" this is not working because my Nuvi was totally dead but after I let it charge the system a little it is working great.
2592859
I did work eventually after a bit of tweaking. As soon as I plugged in, it popped up with instructions in French. I had no idea how to reset it it. The manual reset button in the back of the box didn't work either. I downloaded and updated the firmware update via my laptop which set everything back to English. Working fine after that.