WillFullMass3

I expect a smaller jump. Last time a 1060 was roughly a 980, so I expect the performance of the 2060 to be between the at least 1070 and at most between 1070ti and 1070. It may not matter in the end, but if you need to upgrade everything but not at the same time it could be beneficial to start with everything but the GPU.

I think if you run the 1070 Ti with the 3th gen I'm almost 100% sure that it will be a bottleneck... Now the question is: How much of a bottleneck will it be?

Personally I would upgrade everything but the GPU first and wait for the complete new series of Nvidia GPUs to be released. Even if the 2060 won't be cheaper and/or better performing than the 1070ti, the prices should be shifted in some way or another to make room for the 2050 (ti) and 2060, possibly making the last gen cards slightly cheaper. (Ignore this if you get a substantial discount obviously)