Haven't messed with the Subie, so the dual climate system my change things, but for most typical cars you'd like to see in the mid 50s coming out of the center vent with controls set full cool, max fan, doors open, and idling 1200-1500 rpm. If you'r not seeing low 60s or cooler, you may be low on r-134 (the system only holds about a pound so any leakage really kills the performance) or the fan on the radiator may not be turning. If the radiator fan isn't running, you would probably get cool air when you were moving (due to air blowing in through the radiator keeping the AC condenser cool) but very little when you were stopped.