Certainly if one is going to pick up the car at the airport, it would be silly to pick it up, drive into the city, and then drive out again. But I just want to register for the OP that as a North American, who drove a lot in Edinburgh, it seems totally fine and the comments above all strike me as very overblown. Edinburgh always struck me as a relatively easy city to drive in, with light traffic. Of course, it depends what you're used to. We can't adjudicate that issue here I just wanted OP to hear a dissenting opinion. If you want to rent a car in the city for whatever reason, then drive out, just go for it. Not a big deal in my opinion.