I've had a few ricers over the years and they do offer great value for money in general, but I can't say I have any personal experience with the new GTR (i've never owned any GTRs actually), but as a whole as much as they are good cheap racers, Jap cars do lack a bit of something, i'm tempted to say "soul" but I know how cheesey that sounds, but it's kind of true. Looking at the GTR just doesn't excite me, and i'd be worried that after the initial wow of the gadgets and performance, i'd be left with a slightly empty feeling when you dont feel attached to a car, you just see it as a...well.....a car.
German cars seem to have that word i mentioned above in bags, and I really like the look of the R8, but, and this is what I really think lets the car down, the interior is good because it's like all Audis, but then thats also the problem, if i'd spent the best part of £100k on a car, i'd want it to be a little bit more special than an A5/A4 etc inside, yes it has subtle differences, but it's hardly got wow factor..
If I can draw a comparison, I once had a Nissan 200sx with mods a plenty and more rear wheel fun on tap that is healthy, it was also reliable and actually quite comfortable to drive, but i was never really that attached to it even though on the face of it everything was pefect, compare that to an old battered A4 2.6 Avant I had named "Old Greg" that really was an old work horse, and I very nearly shed a tear when he was condemmed, bizzarre really.
Of course, saying all this, i'd take either the R8 or GTR if they were offered on a plate with out too much fuss!!