Being a former "rexy" owner, my advise is don't drive the GTR like the WRX.
Yes, the GTR does drive like a RWD. It only engages 4WD mode when the rear kicks out. Don't try to counter steer too much when the rear kicks out. Use about half as much and keep your foot on the throttle.
Like any 4WD, brake before you enter the corner to balance it out. Failure to do so and it's understeer all the way.
You may think the WRX is faster out of corners, but in reality the GTR steps all over the WRX.