Give me good convincing reasons for each... So far I'm leaning toward DX first... I would target feature set 12_0 unless there is no reason to go that high since some 11_x is considered 12.

As for Vulkan it seems like the only reason for it is Linux. DXVK can still run the DX12 binaries and OpenGL isn't going away until I can find the time for Vulkan.