I will second that - from experience.
I was recently in China and played on their knock off Gold Crown... I don't know how to explain, but it felt like table was missing solidity... like it was hallow inside or something.
As for Diamond knock off, I didn't see any. So you know, this pool hall I visited in Beijing that stayed pack 24 hours had over 30 9ft tables with 'snooker' pockets and only 1 pool table.
Later I visited another pool room which had 2 pool tables and rest 9 ft snooker style, had Star Tables too but I didn't like it much either. I'm just a table snob

I guess
Another interesting point, I don't think Chinese pool table mechanics/ builders know anything about 'Dyamondwood' either.
S.G.