They all suck.
Consider those ranges EXTREMELY optimistic. And, on most of them I've tested, even with the source/destination boxes sitting on a table DIRECTLY next to one another, they severely degraded picture quality (way overcompressed with crappy compression settings). I'm constantly forced to test these things and prove how crappy they are to our engineering department here at work, because they hate running cables through the walls, and keep trying to come up with "wireless" methods.
So, every 6 months, some engineer comes along and says "I've solved our wiring issue. I bought this little $300 dodad I found online, and it works awesome at my house because I don't have any interference and my test case was a single static powerpoint slide." I really, really hate them. I've never seen (even for $3K+ prices) one that isn't a POS.
It is a very difficult problem to solve.
The bandwidth available on a HDMI 1.4 cable (with the 8/10bit overhead removed) is 8.16gbps (HDMI 2.0 is 14.4gbps). It is difficult for you to squeeze even 1gbps reliably through a wireless connection with high-end gear at low latencies. Pushing 8gbps? That's a pipe dream.
That means something (and with that amount of difference in bandwidth, it is a LOT of something) has to suffer. I suspect most of those systems are capable of 300-400mbps max, and probably more like 200mpbs in normal use-cases, with fluctuating latency. How do you squeeze HDMI down that pipe? You throw the vast majority of the data away, and to keep latencies low, you do it with the crappiest possible algorithms.
