I bought the VMII for my stainless Commander because of the wide spread of the loops.
I also think the VMII is a little thinner overall than the EX Comp.
The only reason I might choose the EX Comp would be if I wanted to use it for some kind of competitive shooting exercise where the pistol has to be reholstered quite a bit. The stiff opening of the EX Comp would of course be best for that.
But for everyday SD carry, the VMII, I think, conceals just a little better plus it's design keeps the rig in place like it's screwed to your hip.