I had a teacher like this in high school for math. He taught algebra, geometry and calculus. He also ran the math team. ( He used to teach at Kenwood Academy in the Chicago public schools where I graduated in 1987 but now he is at New Trier. http://www.newtrier.k12.il.us/person.aspx?id=4450 ). He was a strict, no-nonsense, here is the homework, here is the test, here is your grade, "oh, you didn't understand that, too bad, we're moving on" kind of guy. Was he successful? That depends on how you define it. There is a lot of survivor ship bias. Most kids would have some exposure to him for algebra and geometry and so when calculus was an option kids would think "hmmm, do I want to go through this with this guy?" Those who said yes did well. ( I think students scored either 4 or 5 on the test, 3s were rare and lower was almost unheard of ) The thing is that many very bright, capable kids who were interested in math said no to calculus because of him. I certainly never felt like I learned more from him than any other teacher I had who tried to get everyone to learn the material.

Maybe a better comparison would be algebra and geometry since he taught those classes but other teachers did as well. Did his students perform any better than the students of other teachers? I would say not although I don't have the data to back it up. I had another teacher for algebra and then him for geometry and when I was in his geometry class with other students that had him for algebra I felt we were even. I never felt like the kids who had him for algebra were way ahead of me when it came to doing the algebra that came up in geometry.