A 960 wasn't a very appealing "bang for buck" card when it was launched, and the 3GB variant of the 1060 isn't too, too appealing today.
It's tough to justify a 3GB 1060, with a 6GB version only being in the ~$40 range more - but I would still opt for the 3GB card over an 960 variant........... provided you're not looking to play at resolutions above 1080p