All of this back and forth is so hilarious.
The Nissan is a budget supercar. Those of you trying to compare a sport GT (the M3) to a supersport (GTR) just because the prices are relatively close are completely lost on what this car is. It is these debates why Nissan brought this car out. To once again shake and rattle the world of performance driving.
The GTR is not an upgrade or downgrade to the M3. It's the equivalent of owning a 328i then getting a 370Z. You're just moving to a completely different sports car group. You make trade-offs and you gain better abilities. This is why there is so much debate and confusion.
Most of you making this comparison are trying to treat the cars as if they are in the same category. They are not. Now the Porsche GT3 vs GTR vs Lambo vs Ferrari is a more accurate comparison in which you can truly appreciate the trade-offs Nissan made to break this group wide open. But to say the M3 is an overall better car is to show preference to a type of car category, not the cars themselves...