I used to run a leg bag or leg panel, but after OEF-1, I quit using them unless I was on a hit.
I actually removed my SDS leg panel while on a mission (in order to lay on my side while prone) and ended up leaving it on target. I gave the enemy 2X 5.56 mags, one banger, 2 flex linears, and my personal 5 megapixel digital camera.
So I learned my lesson the hard way. I don't even carry my 6004 unless I just don't have any space on the vest for my pistol.
I can see the positive points of some of these guys uses of drop leg rigs (the Hummer turret is an excellent example), but for me, I try and stay away from them if I can help it.