Calling a raise with an Ace-Rag is one of the worst things you can do, think about what hands people raise with how can you be in good shape?
Of course the higher the kicker the better and id say A8 and A9 are better than below this as you could conceivably beat someone playing a worse ace. Thing is though theyre still pretty crap!
Im known for HATING AJ and its cos it looks pretty good but then often when you get action its AK and AQ, it aint a great hand, ESPESH in a raised pot. I even have nightmares with AQ sometimes thinking about the AKs out there
I know your a tourny man though Kiko and there can be times when your weak ace can be a decent hand, though never great. If your short stacked and you pick up A8 for example. Everyone folds to you on the button, you cant be faulted for pushing all in because A8 should be better than 2 random hands.