As an emacs ex-user I could never live without Caps Lock being remapped to Ctrl, the advantages on Mac are tremendous, I use daily C-a, C-e, C-r, C-s, C-k, etc etc. This is one of the best features of Mac OS in my book, being able to use Cmd for operating system commands and Ctrl for typical UNIXy commands. Whenever I have to use a linux (usually Ubuntu) laptop I cringe at all the Ctrl-Shift-C/V.