Gregtaylor, it depends.
There is nothing that requires the isolated ground to be connected to the switchgear ground, it is an option that the code allows. So if the customer is willing/wanting to pay for it, I will do it. However, installing an isolated ground outlet that has a seperate ground connected to the ground buss bar in a subpanel is a code compliant installation IMO.
I guess I should have a 5th option, IG with ground ran to switchgear. Though I've never had someone want to pay for it during a service call.