I guess my experience is the reverse of most people here...
I have been very happy with the DiMarzios I have tried (Air Classic / Super Distortion / HS3 / YJM ), but thought that I should give SD pickups a try because they are so popular.
Once I got my Schecter C-1 Classic (came with JB and 59 stock), I knew I really like these 2 pickups... that led me to this forum, and to trying the CC. I am still not quite certain about the CC... but I would like to try other SD pickups.
I have also tried EMG... and I think that all 3 companies (SD / DiMarzio / EMG) offer quality products, it's just whatever suits your desired application.
I have a guitar in the shop now getting a fret job and 3 pickups (YJM / YJM / JB) installed.... can't wait to get it back and see how they co-exist