It is never the same twice.
I like the fact you can move to your pace, even though most are on a heart monitor. I don't use one, just judge the dampness of my shirt at the end of the session.
Plenty of times to select from is nice, but I'm a creature of habit and go at the same time.
The entire workout was challenging without being intimidating. My instructor, Nicole, took the time to explain everything to me thoroughly and encouraged throughout the duration of the class. She automatically saw when I needed to push myself harder and when I did immediately check in with me while still being attentive to all the other members of the class.
I loved the trainer Nicole. She wasn't very thorough and motivating. I loved her music and how clean she had us keep the machines throughout class for everyone. I also liked the flow and pace of the class.
It's as individual as you are. The trainers encourage you but don't humiliate you if your not able to do the workout. They provide modified strategies and explain the rational for each. I love being able to have someone else tell me what I'm working on and pushing me rather than me trying to figure out what I'm going to do hat day, all I have to do is show up and give it my best.