Dude. Like the post said, if you don't already know which is the better driver's car, then you might not belong in an MSP. They have their issues, and they're not for everyone. Despite the 3's "40% stiffer chassis", the MSP has world class handling and road feel. You have to drive one a couple of times and take it through twisties and some on-ramps to begin to appreciate it.
I looked at both, and one look at the dash in the 3 did it for me. That dash was designed to wow the easily impressed, despite having (imho) a crappy gauge layout. Then I realized how hard it would be to put an aftermarket stereo in it, and I never looked back.
The MSP is very unique and special. It was made for one year and will never be made again. If you add up the cost of all the aftermarket/custom parts that differentiate the MSP from a standard Protege, you quickly see what a bargain it is. If you want one, get one before they're all gone.