Hard to say because they played a different set of teams. Without playing similar schedules, it's still subjective to who you think had the hardest road. From what I've read, nobody thinks that UCF is better than Florida because Florida was only 9-3 where UCF was 12-0.
just looked it up and pitt played a really good schedule, so this might not be a good argument for me, lol. but i think it's close enough to merit the records as proof enough.
pitt played clemson and nd, while uga only played bama. that's really impressive for pitt (in this scenario, pitt is 1-1 here), whereas uga lost but was really tight in their 1 game.
but uga's has more of the next tier with #10 uf, 11 lsu and 14 uk, while pit had #8 ucf (undefeated) and #12 psu) in that range. uga went a pretty good 2-1 in that stretch (all 3 games back-2-back-2-back, btw), but lone loss was blowout. pitt lost both in blowout.
and last good opp for each were comparable (#20 'cuse and #23 mizzou). each won their game fairly comfortably.
both played a crap fcs team and won handily.
and both rounded out their schedule with meddling teams, pitt going 6-1, uga 7-0.
so in summary, both lost to elite teams close, but pitt has a win too while uga was a really close game. both played a couple good teams, but uga had a good showing and record, while pitt was abysmal. both played decent or crap games for the rest, but uga has no bad losses here, while pitt has 1.
i'd probably put pitt schedule as slightly tougher, but marginally. while uga's record vs their almost equal schedule is much better, even with pitt upsetting clemson (again, in this hypothetical setup). pitt's one luck up win would be enough to overwrite their pretty pathetic record vs every other good team they faced.