Daniel hit on a key point there is a huge difference between class and open gym. My wife and I go to adult gymnastics once in a while at a gym in town and it is is mainly just open gym. One of the coaches is always willing to work with you but there is no scheduled progression.
Definitely give it a go. Open gym is really fun, just getting out on the spring floor and tumbling or playing on the high bar is well worth it.
What we think, or what we know, or what we believe, is in the end, of little consequence. The only thing of consequence is what we do. -John Ruskin