We use Pearl Championship marching drums. Even though a lot of people hate on these sizes, I use the 13x11 snares and the "smaller," 6-8-10-12-13 quints. My bass drums are 16-18-20-22-26. We compete in indoor drumline as well, so I opted for the smaller, "lighter" drums. Is there a sound difference? To a trained ear yes, but honestly it doesn't matter... what matters is HOW your kids play, not WHAT they are playing on. And honestly, I like the sounds that I get from these drums. Does it save on weight? Not really... a pound isn't THAT noticeable. With today's harnesses, a properly fitted harness and drum will benefit more than a lighter drum.
My two cents.