Speaking in very broad, generalized, terms, I tend to find pushpull amps to have a "tighter" more punchy sound than SET amps. But, too much of that quality and the sound seems a bit artificial or "mechanical" and less natural than the more relaxed sound of good SET amps. For me, for example, KT88 pushpull amps tend to be particularly likely to sound too punchy and mechanical for my taste, but, as with everything in audio, there are always exceptions.
I like MANY pushpull amps (this would include OTL amps), while I also like SET amps. It is never as simple as saying one type is better than another. Right now, I favor my pushpull 349 tube amp over my SET amp (the SET amp costs considerably more), but, in some respects I still do prefer the SET amp--although the bass is less powerful and tight, it sounds more subtly "musical" (the quality of the bass changes with the music and sounds less "same" and "mechanical" as my pushpull 349 amp). Both sound harmonically saturated, deliver an expansive and immersive soundstage, and sound relaxed and natural while still being very lively sounding; the pushpull 349 just delivers a little bit more of these qualities.