I've been to Axpona a few times and really enjoyed it. The trick is to make a plan as there are a ton of rooms and people. Go online, determine what rooms are your "must-hear" rooms, and then you can make sure to spend time there.
BTW - I have had luck purchasing demos and b-stock there for sure, just realize they probably won't let you leave with anything before late Sunday if you want to take it with you.