IMHO, Doom without a doubt. It is much cleaner, less buggy, and chooses better packages and configuration defaults in my opinion. It's also even more committed to vim key bindings everywhere than spacemacs is iirc
They all use evil-mode for Vim emulation. So it's just their choice of defaults and configuration style that sets them apart. Doom might have a slight edge with a focus on performance.
Evil-mode is not the only way. There are other approaches like devil you might want to check out.