back in 2010 I was on 245 rubber, 225-230kw. And remember thats an RB20 230kw haha. They were good times hey Ant!
Also it wasn't that 'stripped'. no rear seats but had a half cage. air con out but that's about it. I was regularly driving to track days then.
My opinion.. Ant's and my cars were neck and neck and we both had a ball in the cars we chose, 2WD or 4WD. I'm RWD biased so I think Ant's car would be faster without 4WD but only on some tracks, not all. For the weight penalty you need to have more grip, power down (not all GTRs get front wheel power down with worn transfer cases), brakes etc, so a RWD will arguably make the times 'easier' and cheaper.
Before Ant and I upgraded things in 2011 we were both doing roughly 34-35's at Winton, 47-48's at PI, 24's at Sandown.
Conclusion.. If you want your GTR to go as fast as a GTSt add more rubber, brakes, power and cash haha.