Oakleaf, +1 on your reasons for souring on group fitness. I felt exactly like you did, and I also put myself squarely in the middle of instructors. Well, maybe in terms of "skill (i.e. unique choreography)," not in safety or monitoring. I mostly taught smaller classes, because I taught early in the AM. I think part of the reason I got burned out is that there were a lot people who thought doing weird, hard stuff equalled "better." It's the same when I lead rides. I am a safety zealot and it pisses people off. This is why I actually prefer to work with beginners.
I am taking spin classes at my new gym. They don't have a lot of classes. Although it's 5:30 AM, I still would like a little variety. There's no warm up and all climbing is done standing, save maybe 3-4 minutes. Lots of jumps on Wednesdays. It's just boring. She doesn't correct me when I don't do stuff, as she knows I'm a "cyclist." It's making me want to get spin certified, but I don't want to go down that road again.
I had very good yoga instructors at my old gym and at the one yoga studio I went to. I have only done 2 yoga classes at the new place; one was fine and the other was really too easy for me, but nothing strange. She seemed to be noticing what people were doing. I may try the power yoga class today, just to see how it is.