To note I was also looking at the 1070 TI as well, because the 2070 is only a 10-20% increase in performance but the cards just came out, as soon as the drivers are more optimized I imagine that difference spread will be a bit larger.
Though I think all cards should hopefully be dropping in price in the future too so it should nullify the difference.

From what I can tell the MSI Z370 board seems to be pretty popular.