I've been to IAPPA a few times, but that is because my company is in the theme design business. It is a very interesting convention to attend but not geared toward members of the public at all. Everyone is there to sell products so (like ANY convention) the representatives read your badge to see WHO you are (buyer/seller/visitor) etc. I met people from S & S, Revcheron, B & M, CCI, TOGO etc. but since I was also a SELLER and not a BUYER I didn't too much time with anyone. Depending on your status you get gifts, goodies and loads of attention... (I was walking with a HOLIDAY WORLD owner one afternoon and EVERYBODY was friendly!) Now it may seem rude to be slightly snubbed there, but in reality there are billions of dollars of business being done and there only so many hours in the day for each booth to ballyhoo their product to the RIGHT people.
So, if you want to just pick up brochures, see displays and visit the Midway (about 4 BIG rides last year) you could try to get a Visitor Pass. But I think ACE Conventions or ACE events would be infinitely more rewarding to a non-industry person.
-------------
"You have to scale a lot of lift hills to coast easily..."
Jason