Nvidia GTX 780 Ti vs 1060?

Hello,

I can buy either an Nvidia GTX 1060 3GB, new starting at 245euros, or a GTX 780 Ti 3GB, used for less.
Now PassMark evaluates the 780 Ti as a little faster (8900 vs 8700 benchmark).

What I am asking here is if you have an opinion on performance, directly related to experience in using Unreal Engine, rather than the general benchmark.
Other thoughts on comparing the two, besides benchmark speed are also welcome.
The 780 Ti I am considering, is by Asus. Found nothing about OpenGL in spec sheet, however EVGA 780 Ti specs, say it supports up to OpenGL 4.4. Is it manufacturer specific or GPU generic feature?

Of course you are not asked to evaluate the risk of buying something used, that’s my worry alone.

-Christos

The GTX 1060 should be better, plus it supports some features that the 780 Ti doesn’t.

Purchased the GTX 780 Ti on Ebay.de for (172-30 Paypal discount coupon!) =142 euros instead of 245 euros for new 1060