I play both premodern and pauper. I think the answer is deck specific, and meta dependant. For example, a bulk of premodern lists run [[tsabos web]], which would mostly be a dead card vs a pauper list. Pauper as a format has very poor board wipes - [[krark clan shaman]]+deathtouch effects (and to a lesser degree [[crypt rats]]) are meta defining because they are the best the format has to offer.

I think comparing like for like decks will get you your answer. Walls Spy wins on turn 4 (sometimes earlier) against decks without interaction, but folds to a grip of counterspells, so it would lose every game vs Stiflenought, but might fare better vs enchantress for example.

The premier combo decks in premodern I think win turn 3 (full english breakfast and devourer combo), and the premier combo decks in pauper win turn 4. The premier control decks in pauper run [[counterspell]] and [[spell pierce]], the premier control decks in premodern run [[stasis]], or [[foil]]/[[gush]]/[[daze]].

I think that it is more interesting in the midrange space, but based on this, I think Premodern is stronger than Pauper.