a short click on that link will answer your questions better than I ever could

It's just wierd. Sort of vim-ish, but mostly not. The bindings are really NIH - makes sense to the author, I guess, but it could have been so much easier if a few more of the key bindings were shared with... anything else. It's an entirely new modality I have to switch to whenever I use it.

I think the biggest stumbling block is that it's almost vim key bindings, and the muscle memory betrayed me in the cases where it isn't. I still have to bring up the help occasionally for the stuff I use less frequently, b/c I can't trust it'll be something sensibly from vim or readline.