The work out is great.
However I do feel that to get motivated to push yourself , one needs a great instructor.
I find that the classes I take are led by a very capable and motivated trainer(head trainer).
There's a lot that I like. I like the approach of each class, the monitors to track performance, and the setting/environment the most. The instructors are good and do a good job of running the class, but there's not much of a one-on-one focus. Given the class size, that's something that wouldn't be easy to do, so it's understandable.
I love the trainers! They're so much more than just trainers, they're a support system. When you're mind starts telling you to slow down or you can't do it, they are always right there to yell the opposite. They always acknowledge when you make progress or reach new fitness goals.
I like that it changes every day. I don't have to think about what I need to do... I just show up and know it will be a good workout. Its physically challenging... my muscles are often sore/tired the next day. Its effective.. have lost a pant size in just 6 weeks. I like the "stats" part of watching your heart rate and calories. Staff is really nice and helpful... trainers are motivating.