Well, let me put it this way. I had a lot of fun at Air Force's summer program, but apart from a couple of hours on the last day it wasn't hard at all. At AIM they try and make it as close to swab summer (the summer before your 4th class year) as possible, and they did a very good job of it (I assume, having not experienced swab summer myself yet). It was fun in a different way, but just be ready for a lot of yelling, physical exertion, etc. That's all.