I've owned the coupe model since 8/12 (first 2013 model imported into the U.S.) I love it more than any of the 5 other BMWs in our driveway, far and away.
I would say, unless you plan to track it, just get a regular E90 sedan with the 2.5l motor, which is also a great car. If you can manage 2 cars, still think seriously about getting the regular E90 and getting a dedicated track car.
If you do plan to track it -- I track mine around 10 days a year -- it's really fast, and very predictable. Also, I can load in the same amount of stuff I carry when I trailer a smaller track car with my ZJ, drive in total comfort a few states to a distant track, and arrive rested and ready to go. I'm talking a full set of wheels in the back seat, the tools, the tent, the cooler, the table and chairs, all of it.
Because it's fast and heavy, it eats track tires, track pads, and track gas at a high rate. The only thing I recommend for mods is front camber plates, to dial down the understeer and save on front tire wear.
BMW's real achievement was delivering a real luxury ride that you can use every day around town or for interstate travel, and still tear it up at the track.
Be aware there are a number of owners with main bearing and rod bearing disasters. Also, any service visit is a potential $2,000 - $3,000 bill. If you can find one that's still under the original warranty, Assurant Solutions (the same company that issues BMW's official extended warranties) sells a 5-year extender for about $3,500 through USAA.