I like vi better than emacs in general (it probably has to do with my learning unix without X and basically vi was the only editor to use), but vi doesn't work as an IDE for Common Lisp.
Vial (http://common-lisp.net/project/vial/) was started with that goal, i.e., to provide SLIME-like functionality for vi but it's one of those still-in-progress (and may never actually release anything useful) projects.
Brad Beveridge abandoned development on both vial and slim-vim. He conceded and now uses emacs+vimpulse. [1]
Many people that come to Lisp from vi tend to be very hesistant to use emacs. I spent weeks trying to use vilisp.vim and viper-mode but eventually learned to live with emacs. It was worth it.
That's true. I care about Lisp so that's where I'm starting (hence the emphasis on SLIME more than Emacs). After I get better, I'll probably make an Emacs-only cheat sheet that's applicable to non-Lisp programmers.
