2 seat sports cars excel in lower speed, handling prowess. (Taking corners and high spirited maneuvers.) GT cars are performance cars designed for piercing curvy roads and hard twists. GT's are less agile in cornering and extreme driving maneuvers while GT's are more comfortable in the twisties at higher speeds due to the more stable nature of its overall performance. A true enthusiast would know this... the wannabe would be the person that called the GT car a "WANNABE" sports car???
I myself cancelled my Z pre order and bought a G. (Mainly cuz I was saving 6k on a brand new G which put it in Z pricing with so much more for my $$$$$. Now I'm in a similar situation as you cuz I'm selling my altima to buy a Z. But I'm keepin my G as well. I figure I'll heavily modify the G and lightly modify the Z. I feel the Z is great for what it is and needs little done to it.
The cons to the G imho is...
The steering wheel is less weighted, so it feels slightly less sporty. Longer wheelbase which means wider turning radius, though the G turns mad tight for what it is. (I recommend aftermarket susp set up on G as a ASAP mod.) Lastly the heavier weight makes it feel too stable if u r looking for the jumpy feel of a true sports car. (I think the jumpiness increases fun to drive factor)
The pro's are. Way more features for your dollar. Same engine power delivery. Feels just as fast as Z on highway. Handles better on roads as an everyday car. Better sounding exhaust than Z (subjective). Way more comfy than a Z while still keeping a serious sports car feel.( though a Z is pretty comfy for what it is)
Cons of Z. No back seats. Depending on who is driving,The Z can be awkwardly jumpy and unpredictable
Pros of Z. Short wheelbase makes low speed handling super fun. Screaming engine, louder than G. (That's subjectively a positive for me). Heavy azz steering wheel makes handling the Z awesome and kinda tips the scale Z way.
BUT, I REALLY HAVE NO REGRETS on the G. It is the better all round car though "not" the better sports car. But the differences are pretty minor unless u r on a track.
Me personally, I'm going to sell my altima and re order my Z. I rather not trade because I will lose $4k by doing so. But I'm going to change it from blk chrry to 40th ann.
In a nutshell, the G is a better planted driving car. But in the Z u feel better planted as a driver. Its one of those weird situations that makes it hard to choose...
I guess if I had to give advice. I say go with the G since you will have more room and will have 90% Z feel and 50% more features. You have both cars in your possession so u already know, but sometimes its good to get other perspectives.
hope this helped?