i'd say get the evo if you can afford to.
don't get me wrong, i love my msp. it has good overall performance. i enjoy getting stares everyday at traffic lights, and love knowing that i'm driving around in a limited vehicle that not many people have seen or will have. i'm sure you feel the same way, but is that the only reason that you are keeping the car? if it is, i wouldn't settle. i don't drive around in my car to impress other people because it's "limited". i drive it because
I love driving it.
it seems that you are longing for something better (quicker). if that's the case, then just get the evo. another comment i'd like to make is about this car being a dime a dozen or just a fad. sure it's a dime a dozen (at least in my area, orange county, CA) but i don't consider it JUST a fad. people buy these cars because they're GOOD performance cars. you're not gonna see anything close to that price range that has the same overall performance *stock*.
or maybe you're just bored at work... i dunno