The GTX980 is not a good deal at $220.
Benchmark:
https://www.techpowerup.com/reviews/ASUS/RX_480_STRIX_OC/23.html
You can get an RX-480 8GB Asus Strix for only a little more (or 4GB version for closer to $180 ignoring Powercolor and other questionably low-cost GPU's):
http://pcpartpicker.com/product/hkJkcf/asus-radeon-rx-480-8gb-rog-strix-video-card-rog-strix-rx480-o8g-gaming
Ignoring CPU bottleneck issues, the best-case average for the GTX980 is only 9%, but the RX-480 can pull ahead significantly in some DX12/Vulkan games. Also:
1) better VR support
2) 8GB recommended. already 4GB is starting to be an issue in some games and it will only get worse
3) noise
4) HDR, H265 etc (can look up exact differences).
5) WARRANTY. (how much Warranty does the GTX980 even have)
6) resell value in a year or two
The GTX1070 is the way to go if you can afford it though, and I still recommend the Asus Strix version.
**The game consoles use an AMD GPU. With DX12/Vulkan coming not only will we see improvement with modern AMD GPU's due to ACE etc, but AMD is focusing on low-level improvements like Intrinsic Shader support.
However, AMD is prone to over-exagerrate ( so is NVidia) and these changes take time. NVidia can also improve so the RELATIVE differences aren't certain.
Long-term one issue is lack of asynchronous support. There is CONFUSION on this, so I'll be specific. I mean that newer PASCAL has Dynamic Load Balancing to assist in buffering the different data types like COMPUTE. AMD has similar with modern GPU.
GTX980 unfortunately does not have a good solution for this. It's not much issue yet, but it will result in more STUTTERING in future games likely.
SUMMARY:
The GTX1070 is my hands-down top choice.
OTHER:
The GTX1080Ti is also launching at $700USD. Obviously that's a lot more money, and not recommended if you don't have a really good CPU. If you do, then it's worth at least reading up on the benchmarks. Or you can GUESS at roughly 35% average (for modern, somewhat cherry-picked titles arguably).
*With a good CPU the GTX1080Ti in modern titles should produce 2x the FPS of an RX-480 8GB, sometimes more, and sometimes less depending on several factors.