First off, I'd prefer not to turn this into an infamous I-Club AT vs. MT discussion.
In my case, there are people in my family that occasionally have to use my car, and they don't know how to drive stick. I would've prefered a stick but it wasn't totally my choice. I don't mind it all that much right now though...Seattle is full of hills and bad traffic.
I will just post some of the good things I have found on other sites about the AT WRX.
The AWD in the Auto-WRX is an incredible piece of engineering (tailored for superb handling), available exclusively only in the Auto-WRX and the VDC-Outback. No other Subarus (manual or Automatic, including the manual-WRX), have this superb AWD system.
Basically, the AWD is conceptually similar to what is available in the World Rally conquering Subaru Rally cars, in a much lighter duty form, with a torque-sensing Planetary gear, working in association with an electronically controlled 6-plate heavy-duty clutch pack. Very very rapid torque transmission (front/rear rear/front) with a breadth of torque transferability, that the simple manual-WRX-AWD, can never approach. The torque transmission front/rear rear/front is almost telepathic. You subconsciously want the power to be available in a set of wheels and amazingly, it is available exactly where/when you want it (with the sensors/accelerometers available in the car, doing this), thus allowing you to push the handling envelope to a much more superior level.
In normal driving, it drives with a 45/55 front/rear power split. While accelerating or starting from a stop, 85% of the power is on the rear-wheels. This rapid availability of torque on the right set of wheels (based on conditions), enhances handling to exceptional levels. Something that cannot be said of the manual-WRX.
The main point to be noted, is that the Auto-WRX is equipped with an "Adaptive Automatic transmission". In other words, the trans would learn your driving style and adapt to it (by adjusting the shift points), over the course of a few hundred miles. So driving a "Green" Auto-WRX at a dealership would have a completely different feel from driving a well-broken in Auto-WRX which has adapted to your driving style.