I'm a vim user who started to really get into Lisp (and now ML for school). Emacs (especially with SLIME) is really the Right Thing for Lisp, so I started using it. I've definitely gotten to the point where `C-a C-k` is as well burned into my fingers as `dd` is...it's just that
a) `dd` seems like a more natural keybinding--both because I'd rather double-tap a home row button than involve three fingers and two hands, and because, if you do stop to think about it, `dd` makes sense--`d` means delete, and a double-tap usually makes something apply to a whole line. (Of course, `dd` / `C-a C-k` is just an example--this applies in general.)
b) There's more of a zen to vim. It's been discussed before, but it's worth repeating--vim commands form a language with nouns and verbs. `w` means word and `(` means sentence. Now you know two commands. `d` means delete, `y` means yank, and `c` means change. Now you know 8 commands--`w`, `dw`, `yw`, `cw`, `(`, `d(`, etc. And adding a few more "nouns" brings you up to several dozen with minimal effort. Emacs has no direct equivalent * .
So I like emacs for the ecosystem, I like it for the freakish integration it can achieve between a REPL and a source file...as they say, it's a great operating system--it just needs a good editor.
* - This is not quite true--emacs does try to do sane things with the use of `C` and `M`. `C-f` means "forward one character", and `M-f` means "forward one word"--a "bigger" form of the same thing. In the same way, `C-d` deletes a character and `M-d` deletes a word. But now you want to delete a line? Time to learn something completely new.
Edited to make a lame effort to fix my formatting problems...thus the asterisks surrounded by a sea of whitespace.