I definitely share the sentiment that Spacemacs is slow, which annoys the crap out of me (for a lot of things it feels less performant than Atom/VSCode because people don’t write things in an async way in elisp often it seems).
With regards to vim though, there is no reason for it to be slow, except for some specific plugin pulling you down. Are you using synchronous linters? I thought Ale was async. I would also recommend vim-plug and lazy loading for plugin management.
I’m on Mac myself and use vim regularly in iTerm, Terminal.app and Gui, and am currently not experiencing any problems. Of course, environments vary.
Also, you can try switching out your vim with neovim, which should work seamlessly.
It's not just plugins slow Vim down, a few things that come with Vim are slow too.
The worst is probably language specific support for LaTeX files, particularly syntax highlighting, there is even a tex-slow (http://vimdoc.sourceforge.net/htmldoc/syntax.html#tex-slow) entry in the Vim manual. On my old netbook (haven't heard that word in years!) it was so bad Vim lagged behind my typing, and I'm not particularly fast. I turned off syntax highlighting which fixed the lag, but missed it so much I switched to Emacs instead (and discovered AucTeX which is fantastic, so I wouldn't switch back now).
With regards to vim though, there is no reason for it to be slow, except for some specific plugin pulling you down. Are you using synchronous linters? I thought Ale was async. I would also recommend vim-plug and lazy loading for plugin management.
I’m on Mac myself and use vim regularly in iTerm, Terminal.app and Gui, and am currently not experiencing any problems. Of course, environments vary.
Also, you can try switching out your vim with neovim, which should work seamlessly.