Love my MP3
I don't know if I'm the only one who would choose the MP3 over the MS-P. I did that when I was shopping for a car about a month ago. By no means I am saying the MP3 is a better car without any mod, but it just fits my budget better and looks better IMHO. After pondering for quite some time, I decided to go for a used yellow MP3 over waiting for a MS-P.
There are a few exterior changes that I don't quite like on the MS-P. The color obviously is one. I like the orange, but not even close to as much as I love the yellow. And I don't like the way they painted the top lip of the front grill. Also, I liked the MP3 Racing Hart wheels better than the ones on MS-P. And the orange side markers really complimenting yellow or blue MP3, while the clear ones on the MS-P seems plain on the orange. Not to mention very nicely designed MP3 badges. I love those things.

I also like the minor interior differences on the MP3 over the MS-P, like the cup holder lid, the leather shiftknob(yeah, I don't like the Sparco one that much), the sport pedals(Mazdaspeed I believe?), the print-on 'gear shift diagram' thingy...etc. Very nice.
This past weekend, I got the chance to drive my MP3 around San Francisco downtown, which has quite a few narrow bumpy streets here and there, and boy was it bumpy! Even though I still prefer better handling over ride comfort, but it does make a difference if you live in areas like that. Luckily I don't

. So if the MS-P even have a stiffer ride, it may be quite hard to manage if you are driving your family or friends on bumpy roads.
The MS-P is still great car, and a better car to a certain extend. But with the extra US$3-4k price tag, and a slightly less attractive appearance, I am glad that I chose my yellow MP3. Unless I have a much higher income, then things may be a little different
Enjoy your ride!