I would wait. There is an issue brewing right now regarding the GTX 970 not being able to address the full 4GB of memory. I'd wait to see if this is resolved or if a revised architecture is released. I mean, they still perform badass, but, there may be some issues with performance due to not being able to address the final .5 GB of memory. If you didn't already have a card I wouldn't hesitate to recommend the 970, regardless of that issue. But since you DO already have a pretty high end card, it might not be the best choice right now.
http://www.pcgamer.com/why-nvidias-gtx-970-slows-down-using-more-than-35gb-vram/