I dont know much about the G35 other than two things. It is a sweet car and any Infiniti wont hold its value worth a shit. I was looking to buy a G35 a while back and think they are sweet. But after owning an Infiniti (Q45) and watching it's value decrease more so than other makers, I steered clear. An upside is that you may be able to find one a couple years old that has already decreased in value substantially. But don't expect it to taper off like most car values. My Q45 new was $53k. I bought it second hand when it was 4 1/2 years old for $11k.
Infiniti makes some great cars. I still miss my Q45 and its performance. Infiniti raised the bar for performance causing Lexus and Acura to catch up. The only down side is that the other makers have now brought up their performance levels and hold their resale value much better.