The custom scroll bar might look sorta cool, but it's completely unusable on Chrome. The scroll tracker disappears and it's basically impossible to find. I've ended up restarting at the top of the page just to be able to scroll properly.
Don't get me wrong, I do the same thing, but you have to admit there is a certain dry humor in the fact that you recommended as a best practice to develop exclusively in a cutting edge build of a standards-based browser, only to find that your website is broken in every browser except your development one.