You should always run premium in a Lambo. If you have to use less octane, its not the end of the world. Your ECU should adjust, you'll lose some HP and you may notice Pinging.
About once a year I like to add an injector cleaner to the fuel, find my favorite road and do an "Italian Tune-Up" and get maximum flow through the injectors.
I have a freind who owns a service station and he told me all gas brands are the same and any additives (Techron) are added at the filling station. I try to avoid any "old" station that may have an old storage tank in the ground, which could contain settlement from over the years. Because of EPA, many stations around here are being forced to replace their tanks and I try to always fill at one of the new tank locations.