Are you serious??? I’m sure the NAs are better, but the WRX/STi motors are known to go at about 70-80k. The earlier 2.5 NAs had head-gasket problems too, but that was worked out. LS* run forever if maintained properly (which is basically just oil changes, lol).
Neither car is going to be much fun unless he RallyX’s the Subi, which I’m going to assume is out of the question for a DD/family car. So in that light the SS is better: bigger, quicker, better sound, etc. Though I always do have trouble suggesting anything FWD. 
I guess me real answer is: neither.
-TJ