When I took my 2008 G35 sedan in for some last minute warranty work (interior finish pieces), I was loaned a G37 sedan. I got to spend an entire day in mixed driving in the 3.7.

My comparison:

First off, I'm entirely pleased with my sedan, it's in flawless condition now that the door finisher was replaced, love the thing, passed on an 09 sedan that had awd and black exterior, buying an 11' would not have been a problem budget wise, but historically I only put 5k on the cars/ year.

Exhaust: I run stock exhaust on my car aside from removing the resonators fron the airboxes.

G35 - better sound, at least from inside.

Tranny:
G37, much smoother and easier to launch without snapping necks. The 5 speed in the 3.5 is a little abrupt at times, although more entertaining.

Exceleration:Couldn't tell a difference. Smoothness of the 7 speed I think mutes the feeling of exceleration much like a CVT does IMO.

Interior:I like my heated seat switches over the dials in the 3.7
The cup holder in the 3.7 has a flap that hold skinny drinks, the 3.5 lets them slip around.
The door finishers in the 3.7 are powder coated with a texture, not painted. Infiniti must of got tired of replacing these.

G37 road nicer, more luxury. My g35 seemed to communicate the road feel better, but at the cost of smoothness.

My g35 was prettier, Like I said it's flawless and I blacked out my grill today (had done midnight grill about 4 months ago) - This loaner was beat to Sh@%t even with only 10k on it.

Hope this might help someone who was in the same shoes as I was this past November.

 

I'd love to see the 7 speed in my v36
Thanks for the info

 

I got to test drive the G37 as well. To me it don't seem to be aggressive as the G35. Maybe every thing is really smooth that it's faster and don't feel the aggressive.

 

That's what I felt. Less fun, but more refinement. I'll take fun.

 

The g37 is better hands down but the differences are pretty small. For the money, would rather have a g35 even though it's slower and has much less torque.

 

Well a few mods will put you up w/ the g37.

 

the only thing i really like about G37 (loaner) was the mpg on the freeway with the 7 speed auto and the rear parking sensor.

otherwise, i prefer mine over it

 

I'd put either over the IS350.