Welcome to the club!
Performance wise there is no contest - the STi is the clear winner.
Comfort? With the STi's suspension the WRX has a more comfortable ride.
Reliability? They are both pretty much the same. The STi does have a meatier transmission.
Value? You can spend twice (or more) what an STi does and not be assured of more performance. The STi is a bargain in that respect.
It is all what you can afford.