the performance jump is pretty significant. 1060 is generally reguarded as not reliably hitting 60fps in 4k gaming while the 1070 is. The Frame per dollar value between the 1070 and 1060 is much lower than say, 1060 vs iGPU, but if you are considering a 4k display or you want to push the life span of your laptop that much further, then get the 1070. Since consoles just went through a performance boost refresh to keep the generation going, 1060 at 1080p gaming will last quite some time at high and ultra graphics.