I just drove the G37S and it was pretty impressive. I really liked the interior design but some of the materials don't belong inside a $40k Infiniti. Some of the plastic looked like it was taken from the much cheaper Nissan Altima.
Power delivery was very smooth and linear and felt a tad better than the twin turbo 335i. Although the torque is down 30 lb-ft compared to the 335i the sweet delivery disguises this deficiency quite well. Steering was nicely weighted and the car felt planted around curves.
The car that I tested had the auto trans with paddle shifters. The downshifts were nicely rev-matched but the upshifts were very slow and abrupt.
For about $5-10k less than the 335i the G37S sure is a good deal. Overall, the 335i felt better to drive but i'll reserve judgement until I drive a manual G37S with the 4 wheel steering.
