sounds like they are claiming to work wonders on your bitrate. I think Diaz just pointed out that these claims are dubious at best
He did no such thing. He just pointed out that you can get the same benefits from using x264 directly.
Most people just take the h264 stream they got from their phone / camera / BluRay rip. These are horribly compressed. x264 can consistently improve those without degrading quality by 30% without much tweaking, and by 50-70% with some tweaking.
Apparently, Beamr saves you some tweaking. Diaz' claim is that the tweaking saved is ridiculously minimal and does not warrant all the hyperbole around beamr.