What's that?? LOL just kidding. Actually, i have only 'guided' a couple people through changes with it - and that has been pretty recently. I was first exposed to it during a class in Indiana last month.... it's been an experience for sure, but was able to get the guys from Canada steered down the right path they'd been trying for for months all in a couple of hours time and a few drinks of the Gibson's whiskey they brought me to bribe me to help them....
I at this point have not personally 'done' any UDC tunes form the ground up - just walked a couple people through their modifications and what i thoguht they should change, and it's seemed to work great for them.