I’ve got the older 2007 Z1 RC2, the springs a bit soft, almost needs too much air and they get a bit stiff.
Compression damping took ages to get right though, at first I was bouncing around and they were always bottoming out, running it quite firm feels wrong in the car park and i was convinced they were wrong even over smoother bits of trail, but once they get going through bigger rocks and drops they’re just so controlled, feels harsh, but they only use enough travel to maintain control, not make it comfortable, definitely a fork for going flat out with, they don’t like mincing around .