LEAP is actually C-s. You type "[LEAP key down] f o o [LEAP key up]" to do the equivalent of "C-s f o o [RET]" in Emacs. That's why it's called LEAP. It lets you LEAP to another part of the document. I don't remember how commands other than LEAP work in THE.
The rationale for it is not just the saving-half-a-keystroke thing, it's also that it reduces the problems of modes; since you have to hold down the LEAP key to use it, you can't possibly forget that you're in search mode rather than edit mode.
But I agree totally about the crack-smoking-ness of it physically. My carpal tunnels would explode before the end of the first week.