Where the IS-F gets knocked around a lot by reviewers is it's noticably harsh ride compared to the competition. Performance numbers are close, but every comparison I've seen between the two pick the M3. The IS-F is a hodge-podge of parts thrown together and a stiffened ride. Probably more accurate to have this face off with the next gen M3, when it too becomes a hodge-podge of parts thrown together with a tuned suspension