When I originally moved from Vim to Emacs, I found Viper /harder/ than just learning regular ol' Emacs. I assume "Moving parts" refers to exactly the same problems that I had. I could explain more, but it would take time, because I need to figure out some examples instead of explaining my vague impressions of a few years ago.

Point is, as an avid emacs user, I totally get where he is coming from.