What is the one piece of advice you would give about attending AXPONA?

If you pay to eat at the buffet, get there early. The exhibitor eat like piranha.

one piece?

have fun!

other input?
soft shoes and hydration are great ideas.
locate the bathrooms early on.
pace.
have a lengthy list of songs for audition as said.
see the major rooms or largest demos on the first day, VAC, MBL, . etc.
see as many rooms/demos as is possible thereafter and on Sat.
check out your preff list for gear on Sunday, arriving early well rested and fed.
bring with some music in various formats on the occassion you are allowed to use it/them.

there are likely gonna be too many demos to see them all. see as many as you can stand to see as there will be those which were maybe not on your radar which might be quite compelling.

Pull out the Rolex, comb your hair and wear a sports jacket - that way dealers and exhibitors will give you the time of day. 

Great advise by everyone.
If you like a product exceptionally well, take a pic or 2 so that you can remember what you really "fell for". This is for future buying decision.
I also suggest to keep Shazam OR Sound Hound handy. That way you are automatically keeping track of the new music you liked at the show. I picked up 50+ songs over a 2 day period and created a Spotify list.
Look out for fellow audiogoners :-)

Great advice all.  Thank you.  I did a real newbie thing.  I excited posted my query, then realized that I had not searched the archives.  I did so, and found several threads on this topic.  Still, there is some new advice here and I appreciate it.  I am really looking forward to the experience.

@testpilot - if I only have two out of three of those things, what will that get me?