Difficult to say without knowing your hand size, grip preference and play style. For example, I have a medium-size hand and prefer claw and fingertip grips with a lightweight mouse. So smaller mice work well for me and currently use a G-pro, and also use a g303, Roccat Lua and a Corsair Harpoon. Paladin above me seems to prefer a palm grip, M to L hand size with a preference for a heavier mouse.
Between the two, I would prefer the G403 since it will work for my hand size and grip type pretty well, and it's a bit smaller and lighter than the DA.
Really good info over at Rocket Jump Ninja's
Find a Mouse guide and the
top 40 list.