I've got it on my 30D, and as soon as its available for the 7 i'll put some on that too. It does make the camera slightly more difficult to handle, particulalrly in that it's a little difficult to half press the shutter button somtimes. However, it also adds some bulk, so it makes it a bit easier to use with gloves on.
I find it adds quite a bit of shcok protcection, stops the body getting scratched and also gives an easier surface to grip, both in the hand and if you put the camera down on a surface.
I shoot a lot in boats, and also tend to find that it stops a lot of water getting through to the camera body, as evidenced by the fact that i generally have to wash salt off the camera armour, but not off the body that has it on.