Necessity said:I'd go with WRX. If you avoid the earlier years you end up getting a more stout transmission (than previous wrxs), more syncros, and if you get a late enough model, more displacement off the bat.
The impreza has more aftermarket parts, more companies that specialize in tuning them, and the same suspension configuration. You get AWD (which can be a bonus depending on where you live, it's not in your profile) and a rear LSD.
The bottom line is that both cars ARE brittle. How many 2.0s have blown on this forum? How many lsds have gone out the window? And on top of that, how many WRX owners do you know who have shot their transmissions? You cannot put reliability into the equation here as your key point.
So lets try to list the points and counterpoints.
MSP:
Lighter Chassis
Stock suspension parts are better
Better brakes from the factory
Better stereo (meh, some people enjoy their tunes)
WRX:
Larger Turbo from the factory
More available and mature aftermarket
AWD (could be a bonus, depends on how you look at it)
More HP gains for the $$
Good post and if this were between an STI and an MSP then I like the STI but if it is just a plain Jane WRX then MSP all the way.
The main issue I have had after 103,000 miles on my 12-15PSI daily MSP has been the broken LSD at 103k miles.
But now that has been fixed permanently.