I've got both, and I find that the RSK is just a little too big to keep in my front pocket with my keys, but the mini-RSK does fine. So I always have my mini-RSK in my pocket. When I'm camping though, the keys get packed away, and I switch to the regular RSK.

The other issue is that many jurisdictions allow a maximum blade length of 3 inches, and the mini-RSK is just under that.

They are both great knives, you'll be happy with whichever one you get.