I appreciate the explanation, and I'll say I 100% agree with that. There def isn't an end all be all; I don't really mix that way, but I do tend to put my low end in mono when it comes time to start mastering. I do think doing that usually does make a mix as a whole sound tighter.
To answer the OP's original question, it also depends on the genre you're in. A huge kick in hip hop might mean a heavy one with lot of subs (and hittin hard at 50hz), while a huge house kick might hit a lot higher (100hz+, with a lot of mids and highs).
Anyway, I was mislead before because your first post seemed to suggest just putting it in mono was the solution, which was why I commented. With that said, I guess I don't really understand your comments toward Wallengard because you're both technically saying the same thing.