Dowroa brings up a great point. If the car is JUST purely a commuter car and that's in then the wrx is probaly more then enough. If you are looking for something to mod/race/go fast in save up and get a STI.
It all depends on what your goals/purpose are for the car.
For me I wanted something fast, fun, good handling, and with a warranty. That's why I went from the wrx to the STI. And it's not my daily driver so I could care less how rough the dumps are.