Well having just gone to the 370z from a DE ( 6 years) I do have to say I have not missed the 350z as much as thought I would of.
The 350 as others have said is a more raw driving experience whereas the 70 is quite effortless. To be honest I could quite easily lose my license in 370 as you soon clock up speed without realising it! Looks wise is always going to be a personal preference and for me to really like the 370 it would have to be modded.
The interior is obviously a much nicer place to be, the sat nav and connect premium is a nice piece of kit. Just how cars evole over time.
The Synchro rev is VERY addictive