This is an awesome workout! Coach Chi is encouraging and attentive, and the music was super fun. You are given heart rate monitors and can track your % of max heart rate throughout so you know when to push yourself. The class sizes are capped at 18 (if I'm not mistaken), which means the coach gets personal. You can try your first session for free! Prepare to sweat and work hard :)
UPDATE: I just went to Coach Chi's 500th class of teaching at OrangeTheory. You would never be able to tell because he's just as motivating every single time and somehow manages to have new dubstep/hip hop every class. The workouts are also innovative and you don't feel like you're doing the same sort of thing repeatedly.
What I really love about this studio is that there is something for everyone. People of different ages, genders, and fitness levels all have something they can find here.