The only time I ever yelled at a student was when they did something that put my life in danger and/or were blatently disregarding safety.

In two years of instructing, I had to do this three times. In all three cases they were working on advanced ratings (already had at least a pvt) and I had just picked them up from another instructor.

LAFF will lead you to believe that we just want to milk time out of you. Guess what? Pattern work doesn't do much for us after a while. Having you progress to cross countries, night flying and getting your private to move on to instrument training is much better for our career as well.

Personalities don't always mesh. Working through my ratings I had two instructors that I didn't work well with and changed them as soon as possible. The difference was night and day. You're spending a ton of money, you deserve what fits your learning style and will get you through most efficiently because the flight school will make more money in the long run if you're happy, progressing and continuing to advance your abilities.