I'm a baritone player, I've marched for about 12yrs, both jr/sr corps. I've played on King, Deg, Kanstul. It's really just personal preference, but I must say that playing either King or Kanstul were hands over playing a Deg. To me Degs 2/valve baris are over weight poorly designed horns. Although, you could drop them off a building, have a couple on the field collisions and keep marching with little more than a scratch. Now the new 3/valves Degs are a step in the right direction, but it's still no Kanstul or King.
So now, why do I like the Kanstul or King simple. For me the horns feel balanced with a neutral hand positions, and faster moving valves, not the bell heavy feel of the Degs. Also the larger slower feel of the valves. So I hope was some help.