Ill be really honest, the two dont even compare to each other even driving around the streets.
The GTR just feels so much more rugged, sports car orientated. Poor turning circle, sit low, and harsh ride, feels so much wider etc
And as soon as you give it some stick, and corning the gap widens greatly!
The GTST feels more like a everyday car that is sporty if that makes sense.
Sit higher, easier to cruise around in, more comfy etc.
Still love driving around in both tho! would never swap either for a holden or ford!! lol