Super Joybox 13 for Project 64

I'm thinking of buying a Super Joybox 13 to use instead of a keyboard for project 64. It basically plugs into a USB port, and then lets you lug a gamecube controller into it as a PC controller.
Has anyone else tried this, does it work, and if so, can someone post me instructions on how to get it running please?

from what i understand, its plug-n-play, but i won't trust it unlest you can buy it from an actual store and beat up a clerk to get your money back if it doesn't work.

Nah, I'm getting one from Ebay, and you know that reviews from retailers make the item look heavenly, so I'm hoping for an honest opinion, as I can't refund it.