This makes Emacs great. It is a night and day difference. Multiple times I've tried to transition to Emacswithout it and just couldn't see why people love it. Spacemacs is a great default distribution and solves some major pain points of initial setup and "sane" defaults. There's still a couple things that I'm not quite hip with (installing new 'layers' without restarting, among a few others), but it's probably because I don't know enough about it yet.
As cool as spacemacs is, there are some pain points with it. Try following the documentation to add the mega theme pack. Insert the line that the docs say to insert. (into the file in which they tell you to insert it) Restart Emacs, find yourself stuck in pure emacs. Google how to exit emacs... or open a file and edit it. (If you have no experience with Emacs previously) Yes this is a doc issue, but the point is any misconfiguration, and you find yourself without any Vim-ishness at all.
Strange... Reach out to the maintainers, they act pretty quickly on issues.
On my MBP and the ones of my colleagues, plus my windows machines, spacemacs works great and without issues the last couple of months.
It even convinced 10y+ vim and IDE users to jump ship after testing it for a week.
From my own experience: developing in go, elixir, javascript + react ... It feels exceptionally great with the correct "layers" installed. And being a top notch crosslanguage IDE is just the tip of the iceberg of what spacemacs/emacs actually is capable of...
http://spacemacs.org/