I'd say legit.

I've bought a bunch of cheap Giant stuff in HK (ok, I'm local). For some reason there is an easy supply of AL frames. I bought 3 matching Giant ATX rigid MTB frames for about US$110 each and they've built up to be great general purpose bikes for my rowing club (coaching bikes).

I'd be happy to check them out locally if you want (call some bike shop friends who'll probably know who these guys are).