what does fugitive do for interactive commits that beats git-cola? i love vim for single-file things, but once it comes to a global project view i usually prefer to use another tool.
I have never use git-cola, so I can't compare, but for an overview of fugitive's features, you should probably look into the Vimcasts on that subject. There's overall five videos, this one is the first:
http://vimcasts.org/episodes/fugitive-vim---a-complement-to-...
[1] https://github.com/tpope/vim-fugitive/tpope/vim-fugitive
[2] http://www.emacswiki.org/emacs/Magit