Re: Duncan Designed
My Jackson DK-2S came with Duncan Designed HB-102 in the bridge, it actually sounded pretty good.
I swapped it for a DiMarzio Super Distortion, and while it is an improvement, it's not as dramatic as I had thought it would be.
I have a Schecter C-1 Classic with JB in it, and that guitar sounds amazing.
Basically, if you can afford a JB (or any other after market pickups), go for it over the Duncan Designed, but if you can't, they are actually not bad pickups. (IMHO of course)