An interesting concept for sure. I had actually been hunting for a mathematical description of the Rubik's Cube (being both a cuber and a geek) and this is the first real one I found.
Sadly, the book is terribly incomplete. Joyner fails time and time again to explain crucial information, particularly with his algebra forumlae, and also frequently tells the reader to go read someone else's work for an explanation that probably could've been done himself in a paragraph or two.