Just got mine.
I was skeptical. I needed a way of transmitting my PVR output to another TV one floor above. I have been pleasantly surprised. The signal quality is good even with a WiFi access point running about 10 ft away from the video receiver. I don't see any indication of interference.
I am transmitting from an HDPVR to a standard Def TV, so I can't comment on HD transmission, but I have no complaints about the standard Def quality.
The video transmission, as with broadcast Television, works best with line of sight transmission. I am operating through a floor, but the antennas are pretty much facing each other, about 40' apart
The IR relay works perfectly too. This is a great feature.
For $40+shipping, I think this is well worth it.