I bought my M3 in December with 71k miles...had been looking for one for three years before this one rolled on the lot. It has been everything I hoped, and I've even managed to get 21 mpg combined city/hwy. The ride is a little bumpy, largely because of the tight suspension and low-profile tires. But every time I drive it, I get a smile on my face. I don't drive it hard, but I do look forward to on ramps, and it's nice having "video game" speed whenever I want to pass on the highway. Press the accelerator, and it takes off. The stereo is good, but not great, and the factory navigation is obviously a bit outdated, but still neat to have.
This car is possibly on of the greatest M cars ever built. The car handles like a surgeons scalpel. Acceleration is good, but not great. When compared to my dads car which is an e60 M5, it lacks the "push you back in your seat" factor that you get from that nazi V10. As my daily driver, it is very comfortable to drive around town as well as on the freeway. The SMG is NOT BAD! Treat it like the transmission it is. It is not an automatic. Simply let of the gas when you are changing gear. I do sometimes wish I went for the good ol' standard box, but when driving home late at night, its nice to have an auto mode to take care of changing gear for me. The car has potential for good gas mileage, but if you drive it like its meant to be driven, it won't. We loved this car so much that we bought another one for strict track use. With a little effort and a sawzall, we got her down to about 2900 without a driver. The already insane handling was exponentially increased with some of KW coil-overs and a set of slicks. Nothing more was needed from that 8000 rpm screamer so we left it alone. When in doubt, get the M. You wont regret it.
I was on the wait list for the Porsche 997 and decided to get the M3 instead. I would love to own both but do not regret my decision to get the M3. I have been in or owned and/or driven Audi S4, Ferrari 550, Porsche 911T, Corvette Z06. All are outstanding in their own way. Bottom line is that there is no comprable car for the money. Corvette Z06 is a fantastic performance machine but still in essence a 'Chevy.' The C6 may be different. The S4 (2001) was a great car and easier to modify for more horsepower but had severe understeer and turbo lag. I would rather have the 911 turbo or Ferrari but obviously both are in a different price class.
The exhaust note is too loud and raspy. That may fit a utilitarian, no- compromises car like a 911, but not a BMW. At lower speeds there is a looseness in the gearbox. It sounds like something is broken. BMW says this is totally normal given the car's racecar heritage. I say that's a cop-out. The car is fast but not enough to justify that. The stereo sucks. I've had problems with speaker vibration from the beginning and BMW can't or won't fix it. The car's performance envelope is too far beyond what you can do on the street. Under normal driving, this car is no better than the 330ci. My advice is to save the extra $20k and buy that model.