I bought this sticks purely as 'chop builders' and to work on my technique. I don't play marching drums much, but I play a lot of kit and I use these on my practice pads a lot.
They are VERY heavy, to the point where playing most 'choppy' things I can play with anything from 7a's to 2b's is almost impossible. You need immense amounts of control and focus to play with the same articulation as you would with normal sticks, and I think that is great, and is exactly what I wanted them for.
I don't know if I'd ever use them in a musical setting, but they do create a very different sound to any other stick I own, and they have been a valuable addition to my stick bag.
The only negatives are the high cost, and that you can probably really easily hurt yourself if you use these improperly.