Looks like a complicated and expensive way to avoid running copper. "Up to 1Gbps" is not confidence inspiring, if you really can't put holes in your walls I'd try a powerline kit first for 1/5th the price
What did work pretty well though is MoCa, basically reusing coax/antenna cabling. I get a pretty stable connection roughly equivalent to 2.5G.
MoCa is fine, but if the coax was retrofit replacing it with proper ethernet cable isn't too hard.
He used different transceivers and got 10Gbs