The one thing that most vi-mode implementations don't get is that vi(m) is really about the possibility to configure every keystroke. Its not about "j" is "up" and "dd" deletes the current line.
But in seriousness, although I agree about the importance of configurability, I still find that things like "j is down" and "dd deletes the current line" are an important, integral part of the vi-philosophy.
Placing the most common tasks behind the easiest key-bindings for maximum efficiency and ergonomy is the idea that got me to try out vim in the first place.
I like that someone (Bill Joy and Bram Molenaar) has solved the most common issues in editor-usage in a great way leaving me to configure only some special cases.
