[carguy]

Add me to those who own both an M3 and a Boxster S. Agree with most comments so far. Both are exceptional cars, well built and refined. I haven't raced either, so my experience is based on enthusiastic daily driving.

M3: As you probably know, incredible combination of performance, luxury, practicality. Gives up very little in each area. Surprisingly high limits. Amazing brakes. Great engine and steering.

Boxster S: More of a single-purpose machine. Steering is more direct and immediate. Engine sounds fantastic, brakes are also amazing. Surprisingly practical all things considered with two trunks, space behind seats, etc. Still has the little luxuries, and as a bonus, it's a convertible. That's a big bonus in my view.

Basically, for me, I can drive the M3 in any situation, including passable in winter with good snow tires. The Boxster S will only be used for 2 people max (of course) and for me only in temps above of 8 degrees celcius. Pretty much whenever those conditions are met, I take the Boxster, just because it's more raw fun. As for speed and torque, I find it hard to pick a winner between M3 and Boxster S.

So there you have it. They each offer different things, but both are very good at what they do, and both provide great performance.