Hey Usta,
We are slowly getting up into the bigger northern shows, however, that one didn't make our list this year.
From my experience as a car show participator, detailer, vendor, and attendee, there is the potential to see a bit out there. There are a lot of independent sales reps out there, but as Greg said, many are the ones you see on the shelves at your local Wally World. Some others you'll see and be like, "I've never heard of them", and then you come home and will never hear of them again. Some "backyard" detail suppliers will tell you that their stuff is the best wax out there and blah blah blah, but if you ask them anything technical, they have no clue.
My point is that be weary of what you see and buy while you are there. In the end, have a great time at the show!