I've done a decent number (12 I think) of the Peerless units, with decent success...but with a few caveats.

I won't install them at greater than a 20' distance, and only in the same room.
- note, you may/will get constant break up of video or sparkling especially with motion and 'vibrant/multi colored' images.
- also note that the degradation in picture quality/performance in general is noticeable (if you know what you're looking at/for).

But, when certain circumstances arise it can be a great solution.

We primarily use them in small conference rooms/training centers where floor coring isn't an option or table configurations will change often.

Definitely try not to locate walking paths between TX/RX as you will generally have issues whenever someone passes by.