Thats the question everyone asks themselves.
I went with a 970 for now, and will wait to see what the 980ti pascal equivalent is like. What resolution are you gaming at? If you want 4K the 980ti/Titan is the way to go. For 1080p/1440p a 970 will handle most stuff really well.
I have the z170a Krait and a 6600k, and I'm playing stuff like Witcher 3 and GTAV in 1440p no problem
I game at 1080p (for now). So it looks like 970 is the way to go in this case. Extra horse power would be a waste it seems.