This place is amazing. If you are a U of I student, and you didn't come here to workout, that is a huge mistake. My parents introduced me to Lifetime Fitness when I was in high school, and I thought that was the best of the best. The ARC blows away any other gym chain by far. Every machine you can imagine, an indoor track, multitudes of various courts, an indoor and outdoor pool, a rock climbing wall, and the cave of testosterone (free weight basement).
If you are a student who takes their health seriously, rent a locker for a year and store your stuff so you can be in, out and on with your life. You won't get another chance to workout in a place like this outside of college.