I actually find the immediate feedback from khan academy exercises better than school actually. The feedback loop is much more tighter instead of waiting an entire week later for results and not really getting another go at it. I also tend to zone out or miss something in the lecture, and that missed thing is what builds the entire foundation for everything else and then the entire lecture is pointless. With video based lectures, I can pause, go back, play 2x speed, look at multiple well produced explanations, etc. Ultimately I don't find face to face all that valuable a various amount of subjects.