Not a great deal to choose between them. The 1014 has about 50W more power (if you need it) and it'll do 7.1 surround instead of 5.1. I know it's got a newer processor but I don't know if that will necessarily make an audible difference. Otherwise, I gather they're pretty much the same - except you should be able to pick up an AX3 cheaper since it's a good year older.
I spoke to Pioneer yesterday and they gave me the impression that they had - certainly that some dealers ought to have it. Definitely worth a look online or give Pioneer a call on 01753 789500.