I really don't think that it's going to be as hard as everyone says.
Here is the '12 Legacy GT turbo set-up:
It doesn't look that much different from our exhaust mani.
Here is the '14 Foz engine and turbo set-up:
If they are to turbo the BRZ, seems like an easy enough install to me. The only "real" hard part I see is the piping to the rear of the car.