With Spacemacs, the expected default is to use Vim-style editing, with the addition of the Space key (hence the name) to access all of Emacs functionality. It's quite user-friendly and very discoverable. And it's still Emacs, so it offers a lot of customization.
Doom Emacs is a more focused approach, it has a clean set of defaults, and the ability to load lots of optional features. One key difference with Spacemacs is the use of an extra CLI utility to manage things such as package installation and config upgrades. Doom also disables customize-mode, which leads to cleaner configs at the cost of some discoverability.
Personally, I've been using Spacemacs for years, the key shortcuts just make sense to me, and it includes everything I want. I also love the default theme, the documentation is helpful, and the main drawback, long startup times, is minimized because I never exit Emacs.