Disclaimer: I love all cars, I'm not saying this because I'm a Nissan
or anything.
The Genesis is not in the same class as the Z. It isn't even marketed against it, really. Quality, interior and performance wise it doesn't come very close. Subjectively, the rear styling looks awesome but the front needs some help.
I considered it briefly but once I saw/felt one in person I just had to walk away. TST sums up what I think:
Hyundai Genesis Coupe 3.8L V6 Review | The Smoking Tire