Personally, i love my isf but with that said i recently had a friend who was hesitating between both cars and i'll tell you what i told him. The F is a great car and more exclusive. you wont see as many F's as M3's. the only major problem i have with the F is the maintenance is pretty expansive. you got to figure over a 3 year lease it will cost you about 10-12k of maintenance for breaks, tires, and other minor maintenances. Other than that it's a great car. Good luck!