I wouldn't expect a low end or even mid-range brand-name frame to be better than a generic frame, depending on which "generic" of course. That's the difference. With a brand name you know what you're getting, consistent with that brand.

Personally, choosing a "generic" I'd look for some history. A year or two of reviews, people asking maintenance questions, that sort of thing. I wouldn't just pick something from eBay or a Chinese mail order site, that's never been seen before, and assume that it's equal to a Trek either.