It depends from model to model, as well. Diamond Series is the broad label for *every* production guitar Schecter makes. If it isn't Diamond Series, it is one of the USA made customs.
I picked up a Hellraiser C-1 a month or so back because Amazon had them listed absurdly cheap; $500 for the white finish compared to the $800 everyone else was asking, including what amazon wanted for the other colors. Pretty sure someone made a mistake, the price is back up to where it should be on the model I bought now. The quality on it is good... good name-brand hardware, good finish, good binding/inlays. My one gripe is that the frets are not crowned well. They are level and the edges are done very well, but they are all wide and flat on top. As such they buzz a little if I start getting aggressive with my pick attack. If I had paid full price for the guitar I would have already returned it or sold it, but because I paid so little and I like the guitar otherwise, I'm planning on taking it in for a fret crowning. It really is a good guitar otherwise.
It is one of the models that is still made in South Korea, however, which fits with what leib10 says I suppose. My only other experience with a Schecter was a bass that was Indonesian made that had a broken truss rod right off the bat. I bought it from Guitar Center though, so it could have been something they broke or someone broke and returned without telling them. Still a bit disconcerting.
