370z vs Evo X every day driver.

280z/300zx

Another thing to consider is that in most cases it doesn't make financial sense to trade 1 year old car in for a new car strictly to save money on gas. The money saved on gas would take years just to break even, let alone actually save money. Lets also not forget the Z is not all that great on gas. I do a combination of city and hwy and typically average 22-24mpg. I do have a heavy foot and enjoy the car so someone who drives like a grandma could probably do slightly better. Still, the Z is not at all good on gas. My girlfriends previous C6 Vette was much better considering it had a much larger V8. I could knock out 32mpg with that thing going 80+ on the hwy to California.

As for the suspension, I wouldn't say the Z is any better than the EVO. Both have tuned suspensions that are neither comfortable or nice. For most of us owners it's not something we care about, and I would expect the same is for most EVO owners. If you want a nicer ride get a WRX; still sports, fast and awd but with a much more compliant suspension.

Honestly, if I were in your shoes I would stay with the EVO. The Z is not at all rain, snow, or cold weather friendly. I'm out here in vegas which most people know it barely rains and it's over 100+ the majority of the year. Still, in the winter months when it's cold out I really have to baby the Z. The summer tires on this car suck when temps drop. In Chicago if you had the Z you would definitely have to invest in different wheels and tires for winter, even then you would still have to be far more cautious than if you stayed with the EVO. If I lived anywhere where rain and snow were common place for winter I would definitely be in a STI or EVO. Then again it's easy for me to say because I would still have my 280z and 300zx for summer.