Is this rotating cube interface user-friendly?

I can't recall where I saw a site navigation laid out in a cube but I thought it was unique when I first encountered it. What I didn't realize was the increased engagement the cube navigation led to. It was something new and interesting...I suspect that will be the case with other users too.

The closest thing I can find that resembles it: http://www.paulrhayes.com/experiments/cube-3d/

The author posts that this solution is for a "form that is too long", sometimes that is unavoidable (imagine a mortgage application). A cube based form could help user drop off by cueing the user to what was finished, what is next, and how much is remaining.

Simultaneous 4 form information in 24 hour days 1 cube rotation.

I've been playing with a similar interface that I think would be an interesting way to navigate through comments. It's best when viewed with an iOS device, since it supports touch control, but it works on a modern desktop web browser too by click-and-dragging:

http://oqodo.com/cube.html

dupe, and a dupe that was killed no less - http://news.ycombinator.com/item?id=2996087