Well, you certainly won't be running out of power. 750W is on the HUGE side. But being Gold and with the guts by Seasonic, you can expect good, clean, stable, and efficient power regardless the load you put on it. It should be very quiet to totally silent most of the time too.
I've been in quite a few heated discussions over performance of the i7s vs i5s when it comes to gaming with many convinced, claiming, reporting and advising
that the extra cost of the i7s is not worth it.
I wholeheartedly disagree and note for many serious gamers, the extra money is well worth it. Just because you don't need a V8 in your new Camaro, that does not mean you don't want a V8, are not willing to pay for a V8, or that the extra expense is not worth it - to you.
While clearly you get lots of bang for your money out of a good i5, and if budget is a major concern, then a good i5 (i5-4690, 15-3570, or i5-3470) is the way to go. But if the budget allows, you still get more bang out of a good i7 and it is not the place of those i5 enthusiasts to decide and claim for everyone else, whether it is worth it or not. There is plenty of evidence out there proving you get better FPS rates with most games with a good i7. It may not be a lot more, and in some cases, the gains will not be noticeable (except on paper), but that's not the point. The point is, it is up to everyone to decide for themselves if the extra expense is worth it or not.
As for the mobo, I think, as a general category, the motherboard sits 4th down the list in significance behind graphics, RAM and CPU when it comes to performance. And in some cases, 5th behind drives depending on the tasks being performed. But in that role, the motherboard can either accommodate the other components and let them stretch out and run unhindered, or introduce bottlenecks that hamper the performance potentials of the other devices. So IMO, that Gigabyte (my preferred brand! :smile9:) GA-Z97X is stepping out of the way to allow your other components to shine - a very good thing!