I bought the MR after looking at and driving several other cars, including Corvette, Boxster, S2000, MB CL430, and M3. All of the others were nice, but the clear winner overall was the MR. Plus, the insurance was the cheapest of the bunch (about $300/ year cheaper than the M3, which has the same engine and seats 5!)
I've been very happy with it. Some random thoughts about this car:
I made the round trip drive from FL to D.C. five times in this car, and I'm 6'2". I average about 25 mpg, which is astounding to me because I've been accused of being a lead foot. This car is quick enough to get you into serious trouble with the law! It's got a great rumble and glorious engine noise when you wind it out. Not even a need to down-shift when passing slower traffic because of the abundant torque. Highly addictive. The top is easy to work and I've not had any troubles with water tightness. This is the only convertible I've driven that has low enough side window sills that you don't feel like you're in the bathtub, like in the S2000, Corvette, 350Z, etc.
If you can find one for sale, take it out for a spin. You can't help, but fall for it.