Thank you guys, that answers all of my questions.
From my brief drive of the M3, I can see that I would drive it differently on the highway vs the 335i. Like you guys said, downshift and let her' rip! (Vs the gradual torque of the 335i)
Other than those questions I had, the differences the M3 had were all very welcomed. (Instant and sharp responses vs the 335i's more laid back approach) Not to drudge up this common topic, but I'll just summarize it with one word: Exciting.