Well of course I baised cause I have a 33 GTR.
As much as we all love to compare they are two very different machines. It is very easy to spend another 10-15k modifying a GTR. Of course it isn't all that hard to get 220 awkw from base stock RB26. But above that you have to start laying in the associated mods. Handling wise you also really want a set of coil overs and bars, maybe some adjustable arms if you intend to lower it a bit. Let's be honest, 33 GTR's come from the factory in 4x4 spec suspension height.
Of course as a track car you have a much better handling car. Drag strip you have a car that gets off the line quicker and can put down more power efficently. And a Texi's well - hehe.
Oh, lastely, I also belive the GTR to be safer as a street car because if you hit that wet spot where a RWD car may step out, the AWD kicks in and gives you a bit of edge on controlling the yaw rate.
So I guess the moral of my story: If you currently love your car and are happy with it and will be happy with the outcome for the price, then go for the upgrade.
If you want to step up into the GTR and are willing to some degree - start the upgrade process all over then go that route.