Hi jfofla, I see what you mean. Experienced some losing with AA all-in as well. For me, it depends how well I know the opponents, whether I continue going all-in with AA or slowplay and wait for the flop.
On the other hand, I experienced as well a 789 of hearts flop, with black Aces. This is not an easy spot! So how i see it: if you go all-in with AA, you might get dominated, even by stupid hands such as 35o. If you slowplay AA, you might get dominated by straights, flushes or sets.
Personally, I prefer to still go all-in, simply because - I don't want to give the opportunity to other players to hunt actively for a better hand (flush, straight). That's why i prefer to pressure them to call all-in with 0 knowledge of which cards will fall. If they dominate me with 35o - well, either luck is on their side or it is well deserved because they are very gutsy.
Cheers