AAxx situation I find difficult.

[fuzzbox]

Check/raise all-in is good here. You dont really mind a free card because you have the nut flush draw, and since villain likely doesnt have JJxx or 88xx then he might well bet the turn (but no big loss if he doesnt, as you are drawing to the nuts).

If he bets, you can get all-in and he can't outplay you on the river with his draw if a non-spade card from 7-K hits.

You probably have the best hand, but you are very live against two pair or trips, and a fave against most draws.