Kyle,
No doubt there are more challenging Redans, including those you mentioned. The good thing about Mountain Lake’s version is the word you used: fun. Then, too, I like that it has its own character. What’s the point of traveling if one doesn’t experience something different?
As for being “something different”, I think Mountain Lake as a whole has that covered. Yes, the Raynor aspect is obvious, but in a different setting, one that doesn’t remind me of anywhere else.
One other point I should have made in my first post: Mountain Lake has something in common with St. Andrews Beach, my favorite of Tom Doak’s course. Neither are really about aesthetics. Instead, they are both about hitting golf shots and very quickly, early in the round focus your attention on doing just that.