The main difference is that in Spacemacs, you hit the space bar and you get suggestions of commands to use, then you can narrow those down by navigating those groups. For example, if you want search your project for a file, you would hit the space bar then type "p" (for project). At that point a number of choices appears, e.g. "f" (IIRC) is to find files in your project.

After a while it becomes sort of second nature:

SPC f s - file save

SPC m t f - mode test file (e.g. if you're in a go file it'd know how to run tests for go files).

Another nice thing is that `SPC ?` brings up a prompt that lets you search for commands: you type a keyword for example and you get all the editor commands that match your keyword, so it's easy to navigate your editor shortcuts. That was useful for me, since every result came with the "spacemacs" shortcut, and the Emacs shortcut, so I ended up learning Emacs for free (I was coming from Vim).

Note: I've also tried Spacevim and the only thing it has in common with Spacemacs is the mnemonic key bindings. It doesn't seem to be discoverable (at least not with SPC ?) and it also doesn't seem to be consistent (I couldn't "guess" what certain things were, in spacemacs it's consistent enough that you can guess). Those are the main core pillars imho: http://spacemacs.org/doc/DOCUMENTATION.html#core-pillars