I've found it has less idiosyncrasies, is slightly less tedious in general and provides a lot of the same control, so I don't really see much of an upside to using Vulkan. I don't love the stupid OO-ness of DX12 but I haven't found it to have much of an adverse effect on performance so I've just accepted it.
On top of that you can just use a much better shading language (HLSL) with DX12 by default without jumping through hoops. I did set up HLSL usage in Vulkan as well but I'm not in love with the idea of having to add decorators everywhere and using a 2nd class citizen (sort of) language to do things. The mapping from HLSL to Vulkan was also good enough but still just a mapping; it didn't always feel super straight forward.
(Edit: To spell it out properly, I initially used GLSL because I'm used to it from OpenGL and had previously written some Vulkan shaders, but the reason I didn't end up using GLSL is because it's just very, very bad in comparison to HLSL. I would maybe use some other language if everything else didn't seem so overwrought.)
I don't hate Vulkan, mind you, I just wouldn't recommend it over DX12 and I certainly just prefer using DX12. In the interest of having less translation going on for future applications/games I might switch to Vulkan, though, but still just write for Win32.