The Torch is a non-profit long-form improv studio that offers classes, shows and workshops. Reviewing the classes since that's mostly what I do (but the shows and workshops are awesome too).
Each one has been exceptional. I'm currently in level three and have enjoyed every class so far. Each class is eight weeks long, plus a performance at the end. Classes have at least one instructor--some have an additional instructor in training and taking notes while others have an extra instructor watching from the back for mentoring purposes if they're new. All instructors have been excellent!
It's a fun, safe, budget friendly studio in which we're given just enough side-coaching (direction from a teacher in our scenes) to grow while not so much that anyone gets scared or intimidated.
The torch's core philosophy is about relationships between characters on stage. So too, it's really clear that the Torch community and leaders care deeply about each other, what they've created and what they're a part of in the community.