2500K 4.5 Ghz and a GTX 970 here. I run the game at 1080p with 100% render scale and 4x MSAA and everything else maxed out and I'd say I get 60 FPS 90% of the time, and drops to 30-45 FPS (varyingly) when there's a ton of people around/effects/just a lot of things in general. (Or in the city part of Suramar)
I'd personally say don't use Nvidia's recommended settings. Their recommended for me said to use 200% scaling and other higher end AA shit, which for a GTX 970 in the new revision of WoW is absurd.