Darren, You will have a blast at Carlisle. If you are in to Camaros this is the place to be. This show pulls around 700 camaros in from everywhere. The people are great and and the cars are outstanding as well. This is more of a car event/show rather than a vendor-swap meet. There are still plenty of vendors but not nearly the draw of spring and fall meets (Its GM only which limits vendors). I have never been much of a swap meet person, I rather utilize connections or the internet for purchasing rare or hard to find parts.
Regarding the other brands not being as involved; well all it takes is a little commitment on their part. Its a great venue with lot of potential, which the ACA(Camaro Nationals) has taken advantage of and is growing.
Looking forward to hooking up...