So you think i should go with 1660 ti?It depends on the price of the 1070. If it's at least $280, then I might opt for a GTX 1660 Ti instead. The 1070 has 8GB of VRAM versus 6GB for the 1660 Ti. However the 1660 Ti is one generation newer, and therefore will probably have greater driver longevity support. Even though GPU userbenchmark site shows the GTX 1070 as 7% faster, that is an synthetic benchmark results, and doesn't precisely represent the performance delta in current games. Please watch the video below. Btw, I own two GTX 1060 Ti, in my secondary and tertiary builds.
Hardware Unboxed: Nvidia GeForce GTX 1660 Ti Benchmark Review, The RX 590 Killer Has Arrived!