I like both but in different ways. BMW in general gives me a precise feel, and the M3 has brutal power and is more practical (especially now that they offer a four-door) as a daily car. The preciseness sometimes borderlines on feeling clinical though. I find the Cayman a tag short on power, but provides a very engaging and intimate (2-seater ****pit) driving experience.
I traded my E90 for the Cayman, and am saving up to get a M3 to get the best of both worlds
