AT tend to fare a little better equity
wise, but it suffer from more reverse implied odds. If you hit an A74 flop with AT, there are 24 better 1 pair combinations, and if you hit T74, there are 21 better 1 pair combinations. If you hit K74 with KQ, there are only 14 better 1 pair combinations, and if you hit Q74, there are 17 better 1 pair combinations. That is still a fair amount of reverse implied odds, but its less than AT, and therefore KQ tend to play a little better. AT is also a little more likely to end up with 2. pair than KQ, which is again also a bit of a reverse implied odds situation. If we are talking about the suited combos however, than AT moves up in value, because it can make the nut flush and stack someone with a lower flush.