no it is not!
I'm on a less than 2 day old fresh windows install and DX12 is STILL crashing repeatedly and consistently.
Specs:
Asus z270 MK1
i7 7700k ( tested on OC and Factory ) OC @ 5.0
64GB DDR4 3200 XMP
2x 1080 Founders Editions ( Tested with SLi Enabled and Disabled ) even isolated a card by removing the SLi HB Bridge.
Game is on a Samsung PM960 NVMe with IRST Enabled.
Display is a 1080p Resolution a Vizio 42" M420SV ( yes, i know its a TV, but one with a 3ms panel and works just fine )