I own two GTX980Ti cards (SLI configuration) and it just was not worth upgrading to the 1070 or 1080 cards. I was able to stable overclock my GTX980Ti cards and am able to attain 'near' 1080 performance. For me, that justified me waiting for the 1080Ti or Titan cards for my main system. However, I also have a mini-ITX gaming system and was willing to go with a 1080 Hybrid as it is able to attain >20% gains in most games at 1440P or UHD resolutions without having to overclock (which is limited anyways because of the 600W power supply in my mini-ITX build).
The two main choices for a 1080 Hybrid solution are the MSI Sea Hawk X 1080 and EVGA's 1080 Hybrid. Quite different approaches as MSI's 1080 Hybrid solution is essentially a reference PCB with single 8-pin PCI-E power connector, whereas EVGA's solution is essentially a FTW or Classified PCB & VRM configuration (no confirmation by EVGA on which one they chose for the 1080 Hybrid) with non-reference PCB with dual 8-pin PCI-power connectors. That is the main reason why I preferred waiting for EVGA's Hybrid as I believe it will have a much better potential for overclocking ;-)