That seems crazy to me. A huge fraction of the value of something like vim (vi-clones specifically) is that I can find it on any machine and use it as-is... that isn't going to be true if I expect different keymappings. Even in emacs, I try to use the default mappings for standard things and just supplement them with added features.
TBH, I'll almost never use vim without my configuration files. The only times i might do this is if I need to do a very quick edit to a config file, in which case typing at 50% efficiency isn't going to hurt that much.
