On MacOS I would recommend install macvim with Lua (Lua is required by neocomplete):

brew install macvim --with-cscope --with-lua --with-ruby --HEAD

My ready to go VIM package for quick setup on new machines.

This package is ruby/rails oriented with monokai2 theme by default.

1. Backup/rename (!) your previous .vim folder and vimrc files.

2. Then just install full package (including all plugins):

       git clone --recursive https://github.com/kajamite/vim.git ~/.vim

   If you need more information about every plugin, read their README docs in corresponding folders in ~/.vim/bundle folder.

3. For ag.vim plugin to work you need to install ag itself(if you don't already). Read more here.