I am happiest when there is diversity in my training.
While repetition is important, it can be done by revisiting the same techniques over time, rather than two hours each class just hammering the same lesson over and again (there is a time and place for this, don't get me wrong).
The past week is a good example of what I like doing. Class One: stretches, kicks, strikes, once through all katas, and a fairly lengthy lesson on swords. Class two: stretches (with push ups, sit ups, etc.), focus mitts, light sparring, blocking drills, joint locks/take downs, and a session with the sticks. It was a great mix, and my brain feels like it worked out, too.
We all know that martial arts takes years of repeating a concept, not just specific classes where one technique is repeated endlessly. For example, I have likely done thousands and thousands of wrist throws over the past five years alone, yet never have I spent a whole class just on this one technique--not that I wouldn't. I just think diversity helps, keeping things fresh, and thus allowing greater focus on learning.
Maybe this is just me and my attention span. However, the repetition, if I look for it closely, is still there, just over years instead of hours...
I repeat, instead of hours.... hours... hours...