Shin,

The BMW dealer that lives behind me also brought home an Impreza that had just been traded-in.  It was an STI version and had also been fitted with a "ProDrive" (??) kit.  About ~300Hp.

I had a drive of it about 3 days after I had driven the Z4 M Roadster and I had to give the Z4 the edge.  The Impreza was faster than the Z4, but the Z4 somehow just felt right.  The way it "squatted" under acceleration in ANY gear, was addictive.  The power surge in the Impreza was just too much to enjoy on a public road for a decidely average driver like me.

Definately changed my view of the higher end BMW's (wouldn't buy one though as it's a "club" I don't want to join).