Here are a few other things to note:
As a few people have pointed out here, resale is actually a little better on the G.
Although I'm sure the free maintenance is great, I was surprised how much other things cost. I stopped by the bimmer dealer with my friend who has a 335i, and they were going to charge him $40 to switch in his winter wheels, and $80 to store the summer wheels for 1 season. My dealer does both for free. Albeit, these types of things vary quite a bit from dealer to dealer.
And last but not least, not all G37's are being sold at MSRP.