They'll probably introduce a lot of noise beyond a certain gain level, and will also most likely deliver beautifully shrill sounds, like the old UB-series mixers did... somehow I doubt they completely redesigned the things. If they did, and they sound good, good for them - I just don't think they care enough. Why are you concerned over the quality of these pre's? Are you looking to record, or just buy a small mixer for live use? For live use they would suffice, but then you venture into the realm of build quality on the part of Behringer, which is also shoddy.