So what's the reason people are saying it's a penalty? Simple. There are div's that are hidden. Well, the version I'm building doesn't use many divs. Most of it is just unordered lists with different classes applied depending on the depth. I'm interested to see how it ends up looking and working.
I'll let you know how my experiment goes, but it's fun to play with anyway and our CSR's get a better impression of my design skills. If I can do things our competitors can't, that makes me look good. It isn't tough to build these nav systems, but they don't need to know that. It's just a lot of lines of code.