Here in Norway the Gene-Z and P8Z68-V PRO are at the same price.
If I had to choose I would have chosen the Gene-Z if I was certain I would never go SLI (Which I would be pretty certain I wouldn't).
The Gene-Z is just awesome. You just get a special quality feel when you work with this ROG series board. Even if those extra overclocking features in the bios and stuff like ROG connect are pretty much worthless VS the P8Z68 series, it just has a special feel over it. And those onboard power, reset buttons and diagnosis just looks awesome.
If I bought this I would of course have gotten a cool mATX case.
However, there is no doubt that the P8Z68-V PRO actually gives you more for the price you pay. And are also more suited for SLI/Xfire because of the spacing.
Both are excellent boards, but after my experience with the Gene-Z (System I built to a friend) I just got a special feel about it. I just loved it