Any ring time is good time. Never a waste.
I'd be in the ring for every run offered with each of my dogs if it was feasible. However, when you run four dogs sometimes you have to be a bit choosier about you enter. That's when goals come into play. And since the All Around is not one of my goals, I tend to spend my money on classes that will help me achieve the goals I do have set for myself and my dogs.
My new dog got entered in Hoopers at her first trial this month because I figured it would be a low-pressure easy class for her to get some ring experience. It's nice for that sort of thing (doesn't require the brain power of weaving or contacts, for example).
Personally, I have many other ways of testing my handling and challenging myself more than Hoopers does. I enjoy Hoopers, but just don't have the money to throw at it anymore. It's not like we don't see plenty of hoops in the other classes anyhow...