The current WRX, Impreza, Liberty/Legacy/Outback and Forrester are based on the same floor pan as released on the original Liberty in 1989. That's why many of the suspension parts are interchangeable. The original platform was not designed for performance, but rather for reliability, potential ground clearance, passive safety and above all else, ease of manufacture.
Handling Issues.
The WRX is a poor handling car with great grip. In a pure sense it does NOT handle well, but is saved on the limit by its all wheel drive. It will not please WRX owners to know that the WRX is consistently knocked off at the race track (tarmac) by 200SX's and many others, but they lead on the dirt. Again, more grip than handling. The WRX really tested the original design because of its enormous acceleration. As any WRX owner will confirm , powering out of corners means nose up and loads of understeer as the weight shifts to the rear and the front tyres scrub for traction. Power launches will see the nose lift while 70% of the available torque tries to find a release through the front wheels.