I had to re-read your comment. At first I thought you were saying you had one hour of homework per night. One hour per class per day is insane.
I regularly avoided doing homework throughout my school life. The only thing I think that suffered was my understanding of physics & chemistry. I doubt I would have better understanding now in any other subject area if I had done more homework, including maths and the foreign language I studied. Maths because we were given enough time in classes to do exercises in which to learn the concepts; foreign language study because it just wasn't taught terribly well and the homework was in the same vein.
I regularly avoided doing homework throughout my school life. The only thing I think that suffered was my understanding of physics & chemistry. I doubt I would have better understanding now in any other subject area if I had done more homework, including maths and the foreign language I studied. Maths because we were given enough time in classes to do exercises in which to learn the concepts; foreign language study because it just wasn't taught terribly well and the homework was in the same vein.