About a month ago, I was in a similar dilemma. I narrowed it down to several cars, and the fact of having a backseat and AWD spec was making the G37 a favorable choice. However, I stuck to my guns because I really liked the body lines of the 370Z specifically and done the cross-breed sedan sports car already; i.e. 330i and WRX.
Just my own
personal biased feelings..everytime I see a G37 up close nowadays, I pat myself on making the
right choice for me. I really dislike the appearance compared to the Z.
If I needed a DD with backseats and had a family, the G would probably win-out; but I am sure I would've talked myself into a 335x, if that was the case.