Keep in mind I have the pre-2013 base model 2.0. I have the 210hp rather than 274 on the 2013 2.0 or even 306 for the 2012 3.8. Stock, my car hit ~165 hp to the wheels. Barfffff lol So stock for stock going from mine to the Z would be a big upgrade. After the few mods I've done, I'm now at ~210hp and 230tq to the wheels but still a good bit less than a stock Z. I don't plan on doing anything more with a Z than I have with mine which would be intake, exhaust, and a tune. I just get nervous about giving up a couple years, the miles, and warranty to trade back. From what I've seen though, aside from the few common things I've read on here (steering lock issue, fuel starvation, and oil temps) the car seems to be pretty reliable for most. And if you're wondering, yes my genesis is an auto and I'd go for the auto Z also. I know I know...Can't drive, gtfo, no stick no dic*, yada yada yada haha
