I've had the good fortune of getting into some really good lessons.
@Skier31 and I have similar experiences and in fact, I'd take a lesson from her in a heartbeat.
I don't get too annoyed by an instructor as long as he/she can communicate like I like to learn.
One of my first lessons ever, I recall spending some time with the instructor talking to us at the beginning which I didn't understand at the time but he was simply getting an idea how we all learn. Someone may learn by feel, some need a demonstration and some (me) need to learn in layers, creating buidling blocks to get the end result.
The only times I got really annoyed in a lesson was when a clinic leader kept telling me to do something over and over and I wasn't getting it. Other students were, but not me.
He eventually said, "Trek! I keep telling you what to do and you're not doing it."
I replied, "Right? I'm not getting it and you keep telling me the same thing. Find a different way to tell me!"
Two days later I took a lesson from someone else and explained the situation. This new instructor had me doing it within two runs, mainly because he gave me the building blocks to make the move and then I felt it. After that I could go off feeling but I needed the mechanics to get there.
I guess I like an instructor who has the ability to teach each student in a manner that works for that student.
FWIW, I tried to be an instructor but after a rough winter making the attempt I realized its not my jam. Total respect for those who have the patience and skills to instruct.