Some of the config basics are the same. You check for file type, and then set some overrides for make commands. Plugins provide asynchronous compilation, error listing/highlighting. The worst part of working with vim tooling is vimscript, hands down.
Neovim is making nice strides towards modernizing vim interfaces and support, and providing Lua as a vimscript replacement.
(Diehard vim keybinding user, but editor/IDE nomad)
For an expert, I'm not sure that there is anything that st3 has that cannot be achieved by the other two with a combination of plugins and customization.
The biggest difference I have seen is reasonable defaults for a new user. I have lots of friends and coworkers who use Sublime because dropping into vim/emacs is like entering an alternate dimension. They expect to click around and edit text similar like any other program on the computer (which vim lacks) and have a sensible menu system (which emacs lacks). Sublime uses standard system keybindings, so that e.g on a mac Cmd-S saves the current file like you would expect. This is possible to do on both vim/emacs, but not the default. It is really difficult to convince a brand new user that the first step they need to take is opening some random hidden file and customizing their entire editor in a custom configuration language just to get the system default behavior.
Highlighting that isn't painfully slow. Handling of long lines and huge files without massive lag. Better DSL for syntax highlighting. Native Python scripting.
Some of the config basics are the same. You check for file type, and then set some overrides for make commands. Plugins provide asynchronous compilation, error listing/highlighting. The worst part of working with vim tooling is vimscript, hands down.
Neovim is making nice strides towards modernizing vim interfaces and support, and providing Lua as a vimscript replacement.
https://neovim.io