Ok, I'll bite. I take it you're specifically talking about the GT-R models here as the GTS Skyline or the Silvia/SX range are as plain RWD's as plain can be.
While I can't talk with experience on the R35 as I haven't driven one, atleast the older the GT-R cars still manage to feel natural even with the 4WD system working its magic when required. It's hard to describe for people who haven't driven them, but most of the time they feel just like a powerful RWD car with tons of grip.
Kovalainen seems to really enjoy driving his R35 aswell, he doesn't seem like a guy who would buy a car that he doesn't like to drive.