Someone always has to disagree, right ? I'm not disagreeing with the 2500 (owners here really like them) but I wouldn't feel you have to rush into getting a new receiver. I don't have any experience with the 502 but it does seem like a pretty decent receiver.

Again, not saying you shouldn't upgrade, just don't feel you need a new receiver before the Axioms arrive

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8