Um, I've never heard of Jungle King Leo, much less seen it, and now I don't think I would want to if it takes away the joy watching the Lion King brings. I love the Lion King!! It's in my top 3 favorite Disney lil-kid movies (lol, it's hard for me to have favorites w/ regular movies or books, so this is like the only thing I'm able to have favs of, don't ask me why, I don't know).
You learn something new about it when you watch it anew-for example, don't tell me that as a kid you actually knew that the stars really are great big balls of gas flying billions of miles away so you could get that joke in the movie
It also tells a great story too. All of my friends think that it's a really cool movie too (for a Disney one). Imo, if you hadn't seen Jungle Emperor Leo, you would still love that movie (or at least think of it in better terms).