Even though it puts me squarely in the minority, the All-On setting is my preferred setting, I use it all the time. I had all of my ABZs built with the D-Roc switch and the S/P switches. It sounds massive, but it's still very controllable. Honestly, I could've had my basses built with just the All-On setting and one S/P switch for the Neck pickup and I'd be just as happy as I am now. I do mess with the other settings, when I'm at home, just to see if something moves me, but invariably, when I'm about to hit the record button, I flip it back to pos. 4 and go. It just works for me.
Congrats on the Z! When I finally get around to ordering a Z3, it'll have the D-Roc switch. I really want to hear three SF-II's at gig volume!