I can't tell you about the Chinese frames, although I've read other threads that seem to say that they're very good, but a bit rough round the edges (poor finish etc.) although one guy posted a horror story about them. I guess, you pays yer money you takes yer chance!
As for the integrated seat post thing. I've just got a Ridley Helium with an ISP. Whether an ISP is worth it can be discussed ad nauseum. What I can tell you is that my "cutting" experience was very good (though harrowing at the outset). Once the bike had arrived (mail order) I took it along to the LBS, which had a funkatron machine thing like an exercise bike, which could put the bars, seat and pedals in any position. Once we'd found the right position for me, my bike was handed over to a grinning engineer brandishing a hacksaw while the shop assistants held me back with calming words of "Trust us, it'll be alright, we've done this before."
10 minutes later my bike was presented to me and it's been a perfect fit ever since. So, in short. For an ISP, leave it to the professionals. 9/10 times they'll do it right (ok, hopefully more than that).
After that, the only problem is selling it on afterwards. But I imagine I'm going to keep this bike for a while, and I can still adjust it up to 9mm (or cut it down more) and Ridley provide a clamp which allows up to 40mm adjustment. I imagine the Chinese brand won't do that though.
Oh, I've just found the link to a thread on RBR which might answer some of your questions. It's quite a hot topic, it's the third major thread they've had on Chinese carbonhttp://forums.roadbikereview.com/showth ... p?t=225409