I love the classes taught by Rory, Erin, and Stephanie. (I haven't tried Scotty yet). They give you a solid workout...without the alpha screeching, which I avoid like the plague. All teachers are absolutely competent, but personally, really dislike it when some of them start yelling and get bossy -- instead of being motivating, it's agitating.
However, I get that maybe some need it. Thankfully, there are some who avoid those tendencies, and give classy sessions that give great workouts.