Get a new screen before either. 60hz will hamstring any benefit either card offers.
I would keep the 1070 until AMD releases their cards and Nvidia (hopefully) drops prices.
But if you are committed, the 1080 Ti has more raw graphics power. Sure the RTX has the RT cores but its the first generation of this technology and I generally wait for the 2nd or 3rd so it can mature and I would want to make sure the technology isn't a fad that doesnt last (like PhysX).
Asus Prime Z370, Intel 8700k @5.0Ghz, Nvidia GTX 1080 Ti, 16GB @3400 CL14, Watercooling: x2 MCP355 pumps, x1 280 on front of case, x1 360 on top of case, x1 140 on back of case, x1 240 on bottom of case
Last edited by StAndrew; 04-30-2019 at 02:20 PM.