Damn! i guess i hadn't realized the 06 MY had the 2.5 liter engine... sudenly i find myself not wanting it quite so much... mabey i just need a test drive of it soon.
and regarding your clutch wear... itts definately realistic that it wouldn't last as long. but also, your low gear synchromesh (1rst/2nd) may or may not be an issue.
i know a MY 2002-2005 are said to be able to handle about 280 hp, and i dont doubt similar torque numbers. im not sure if any of the other internals were changed with this model year; but replacing
all in all, it couldn't be terribly expensive to upgrade to the STi clutch... that one is said to be able to handle 600 hp or so
post some pictures of your car, such im a WRX lover myself