I'm new (a few months) but I like that each workout is different, and you can challenge yourself by speeding up. Also, variety assures that I won't easily plateau. I have a long way to go, but I already see and feel some positive effects, and if it gets easy, I just increase the speed.
Only bummer: waiting for shower, sometimes as long as 1/2 hour.
The trainer quickly recognized that I was new and helped correct my form on the workouts I looked lost on.
If I could make any suggestions for areas needing improvement for the trainers it would be to try to engage the crowd to interact with each other. Once a block completes "Hi five your neighbor to the left and right of you for doing such a great job" or at the end of entire workout give yourself a hand for getting through this challenging workout!"
We're all here to get in shape or maintain and giving each other this positive feedback is what makes OTC different from the other gyms. The sense of community.