Yeah it worked really well on Halo 2. Run, Jump, Toss a grenade(would drop second weapon), hit the ground run and pick up my second weapon at the same time. It doesn't really apply that well to Halo 3 as I don't dual wield as much anymore.
For those, who don't know how we inverts play the game, I just feel it's unnatural to look up and not think of pulling you head back(or joystick). I will say that certain games I can't play inverted for some reason, they just don't feel right. It's a spatial memory thing, right brain vs. left.