$650 to play what AAA game. There is nothing else coming out this year that would use that shiny 980 Ti. I already posted, no new Mass Effect, no new Elder Scrolls, no new Fallout (unless Bethesda just stealth drops it which I seriously doubt) Just Cause 3 is likely next year. High vs Ultra in Witcher III is next to irrelevant beyond screenshots, er - ? AAA releases are drying up - V and Witcher III have launched and those playing Day One like me are already finished or a third of the way through respectively.
And I doubt I'd consider AMD, it took them a year+ to release WHQL drivers, Nvidia has Day One drivers (and guides) for big releases. That alone is worth a premium.
And I'd pass on any reference card. You buy top shelf you want a top shelf cooler not some stock rubbish. Its like buying a K processor and keeping the stock cooler. And the Ti is gimped too, less cores and less textures units. Meh. Damn I'm getting old and grumpy.