For those of you building a new X399-based system, this review of the ASRock X399 Phantom Gaming 6 should be of interest to you.
At $250, the Phantom Gaming 6 is the least expensive X399 motherboard, which is its main selling point, and a good selling point. While you are limited, especially in overclocking, to the 180W SKUs, the motherboard is still a great bang for the buck.