i can tell you right now 02 and 05 STi are totally different cars
even the 03-04 is different to the 01-02
power and weight may be the same but thats where the similarities end
how can u say the 2L is better then the 2.5L? are you normal?
2.5L has a shitload more torque.
once you start to get to the high 11s its time to bin the 2.0 and go for a 2.5