The workouts are challenging but doable for any fitness level. They are always different which keeps the workouts interesting and works different areas of the body. I always feel a sense of accomplishment when I'm finished and look forward to the next workout.
Variety and fun! I enjoy that it does cardio as well as strength training. I also love it's a full hour of getting your heart rate up and seeing what zone you're in on the monitor is helpful with motivation.
I have already had 2 people join because of my success with the OT workout. I love being able to workout along side friends and still be able to challenge myself at my own pace. This is the only workout that I have had this much improvement in the tone of my body. I'm definitely hooked!