That's fine until you find one damn machine which has a buggy version procmail or a vim version which is too old for your filetype/feature plugins, 5 versions o

That's fine until you find one damn machine which has a buggy version procmail or a vim version which is too old for your filetype/feature plugins, 5 versions old emacs or an old version of bash etc. It's never "just that easy". Past startups with heterogeneous kit, keep it simple.