Intensity. Don't have to think about what to do because it's already planned. Coaches repeat instructions at each interval. Coaches explain and correct form when needed and explain how to prevent injury.
I love to train there because I always feel myself motivated to train hard, I can do excersie with other people, the routines are always different, the equipments are excellent, and the coaches are really good and nice. There are a lot of classes during the day and you also open on weekends so that is amazing!