Amazing overall balance. The designers of this car have their fundamentals straight. Even the interior ergonomics affirm this as the dash is angle toward the driver (a hallmark stamp of all BMWs). This car is about the art of driving. It has excellent acceleration, handling, and braking. You can push this vehicle, and it does not lose its composure. Try the new Michelin Pilot SX tires -- they're a great match. Also, this is not a flashy sports car that screams "look at me," which I consider to be a bonus. Some might feel, in fact, that it looks too similar to the 318 line. However, you're less apt to flag the attention of the Highway Patrol in this car, than you'd be in a C5 Corvette. Also, this is a practical car. I can fold down the rear seats and have relatively enormous carrying capacity for a sports car. This is a car that you can drive every day with little hassle. Overall, the M3 is technologically sophisticated, subtle yet competent, highly refined, and fairly priced.
Starting with important things first: the M3 begs for a 6th gear. First gear is great for racing, but on a practical day to day level, you must shift to second sooner than with other cars or else you'll be revving very high. Maintenance is very expensive, and dealers are, in my experience, not the most accommodating or responsive to customer needs. Their prices are high, and they charge ridiculous rates to fix even the smallest of problems. If you buy this car, be mentally prepared for this, and you won't be as aggravated. Consider it a hidden cost of ownership. The front air dam is LOW. If you own this car for any length of time, you'll probably at least partially rip off the front air dam at least once (by pulling into a parking space all the way, or on a slope in a parking garage). And you guessed it...repairs are not cheap.