That's at 1080P, if you look at the 4K results on the same page the 290X 8GB wins in min and max FPS against the 980, I wasn't referring to peak FPS anyway but the 290X does pull ahead at higher res there.
What I was originally referring to was less / drops stutters with more vram. The 980 generally does get higher peak FPS than the 290X / Titan Black etc, but from my own experience, games that need a lot of vram Shadow of Mordor / Wolfenstein run much better for me, smoother / no stutter on the 290X 8GB. I game @ 1440P with 290X 8GB. My boys love the 980, they game at 1080P.
You can see how much the extra memory buffer helps performance. Playing the game with both the 290X 8GB and GTX 980, the 290X 8GB does give noticeable better game experience, smooth etc. As games are only going to get more demanding, the 290X 8GB makes a lot of sense, especially at it's current price point. I'm going to hold out for another 8GB card before upgrading, unless DX12 really does find a way to remove the limitation with tiled resources or something. Tbh though I'll just wait for 390X 8GB, or if I absolutely must an 8GB GM200 (I really don't want to have to go to the dark side
)