I tried spacemacs for a while but I got tired of fighting all the little idiosyncratic differences from real vi. Trying to replicate a sophisticated interface like that, especially one that allows the buildup of muscle memory, is always going to be a fraught problem. It's the Anna Karenina principle [0]:
Happy families are all alike; every unhappy family is unhappy in its own way.
And it integrates many "vimisms" via evil-mode. I'd been a vim user for a long time but was increasingly dissatisfied as I got deeper into extending it. I've found the opposite of emacs (especially with spacemacs) almost a year into the "conversion".
One example that I've come around with was an initial extreme distaste of dynamic binding/non-lexical scope, from a PL standpoint of writing robust software.
But it's also super nice for incremental, interactive development.
Having tried spacemacs, I bounced back to vim. Even though vim is just a tiny bit more responsive, it's enough to make emacs feel laggy. Granted, I use extensions very lightly, so I'm not feeling the qualitative difference of being able to do something in spacemacs that's impossible in vim.
What do you mean laggy? In the response time when typing or the time to start a new instance of emacs? If it's the first did you try emacs -q to check that you don't have something strange in you setup. If it's the latter, did you check out emacs --daemon ?
I did give emacs --daemon a try, and that definitely helped with the long startup time. I went so far as to alias vim to emacsclient -t. But what I mean when I say it was laggy is that typing and cursor movement are ever so slightly less responsive. Not MS Word on Windows 3.0 laggy, just enough for me to notice the difference. I dug into it a little bit with spacemacs and vim open side by side, and according to top, spacemacs was using about 10x the CPU of vim.
