To OP:
I think your speakers are good for their budget, but besides support for 3d you're not going to get better sound. Speaker is what you should be looking to change if audio quality if a priority
Speaking of speakers - you didn't mention a sub. Do you have one?
If 3D support is a feature that you must have, then A800 is the way to go, otherwise I'll the old avr and look to upgrade sub/speakers/room treatments