I just ordered a Duncan Distortion. I'm using it to replace a JB (bridge) in my ESP Eclipse (not LTD). The reason I was replacing the JB is because it's mid spike is a little misplaced sounding to me, and the bass isn't tight enough. Also, when clean the JB sounds a little thin to me, but that could be b/c it's counter part in the neck is my '59, which is pretty thick in comparision. The Custom and Distortion were both recommened to me as replacements for the JB, and after reading some product reviews and scrutinizing over the sound clips on the main site here (which is really difficult I'll have you know), I went with the Distortion.
I'll let you guys know what I think when I get it in.