I couldn't know EVGA RTX2080Ti K|NGP|N will be so good and EVGA X299 Dark.
I would miss X99 and wait X299 Dark, install i7-7800X and now upgrade to 10920X. But again RTX2080Ti KP is too expensive and out of my budget.
Because X299 Dark and K|NGP|N are really top combination for guys not plan to upgrade so often, exactly as I imagine high end PC.
No matter on performance and TRX40 AMD combinations not attract me so much.