I have a 94 850 turbo sedan, FWD, and a 98 R AWD wagon. I much prefer the AWD over the FWD, the handling is much better...no torque steer, better balance...no wheelspin at front.
As far as reliability, the wagon has been great, even after re-tuning to 290 HP.
Like any AWD with viscous coupling shaft, all tires / wheels must be the same size / type. Also inspect all drivetrain parts (covers) every year, if a coupling cover breaks and exposes the part, lubrication is lost, and big bucks to replace. Flush transaxle every 15 k miles, cheap but good maintainance.

Wills