So far so good with the formula and 3900X. The 0702 BIOS version is stable and boost clocks seem to be working correctly (based on HWINFO64). I've had luck running B-Die at tight timings with lower voltage (3400CL14 1.375V) or higher frequencies (up to 3600/CL16 so far). Far more stable of a first day than the C6H was.
The chipset fan is inaudible, though I do wish they had found a way to tie it into the VRM water loop. The integrated M.2 heatsink is a nice touch.
There is no utility for the Livedash yet but the default functionality is useful - POST codes at boot and CPU temp after boot. There is also no mention of it in the manual.
It took some trial and error to identify which USB ports were functional at POST.
I wish there were a few more extras in the box for such a premium price point. The antenna is not magnetic like older Asus boards. The included documentation, stickers, etc were all warped like they were in a high moisture environment and the protective plastic seemed dirty.
I played with the automatic overclocking in the Asus utility and it didn't really seem to work. It picked 4.15GHz for all cores as well as 1 core. I don't think the single core modes are functional yet (the manual interface didn't give any control either).