I have a few patches that speed up its git plugin by letting you opt-out of expensive operations. https://github.com/davvid/oh-my-zsh/commits/davvid
Last I checked, oh-my-zsh was in transition to a new version(?), and the pull requests have generally been ignored because of this.
ZSH_THEME_GIT_PROMPT_DIRTY=""
ZSH_THEME_GIT_PROMPT_CLEAN=""
which lets it avoid expensive checks that my prompt doesn't need (it already shows that info elsewhere).The real big win is that I export `POST_1_7_2_GIT=1` in `~/.zshrc` and the tweaks I made teach the git plugin to use `--ignore-submodule=dirty` when calling `git status`, which makes a huge difference.
I haven't caught up with oh-my-zsh in a bit; if there's a good place for me to rebase onto and do a new pull request I will. Does anybody know who the real oh-my-zsh maintainer is these days?
In my plain gnome-terminal with git it would instantly autocomplete when I pressed tab.
Not using oh-my-zsh or the like, zsh has lots of hooks and omz uses a lot of this hooks for or around git repos, so CD-ing into a git repo entails loads of work.
Use vanilla zsh and configure as needed, and it'll be as zippy as everywhere else.