I love Barre3! Every class I've taken has been challenging. During my first class, I definitely thought my calves were going to burst outside of my body. Luckily, I survived, but if you're looking for great instructors that work out different muscle groups, definitely take a class. If you're also looking for a more modern, badass approach to barre (vs. classical instruction), definitely take a class.
What's also notable about barre3 is how friendly everyone is. The front desk, the instructors, the other students, it feels as if everyone is one big family. I wish I lived closer so I could come more often.
There's also childcare and a cute retail area. Barre3 also likes to host events and I know they had one at Mountain Shadows a few weeks back. I had the opportunity to attend a separate event where I heard the owner speak. She's a sweetheart and I respect her leadership. Go check them out if you haven't already.