(soon to be Z1U owner ...)

I've read http://adamwilt.com/HDV/cineframe.html , the excellent reference on the CF modes.

Anyone know if the CF24 is slightly better when the Z1 is booted-up in PAL than NTSC mode?

Actually there isn't any CF24 in PAL mode, only CF25. If you read Adam's article he feels that the CF25 and CF30 modes are superior to CF24. When we did the "Texas Shootout" and tested the other cameras in 24p mode we set the Z1 for CF25 because Adam felt this would be the most comparable setting.

I have read this elsewhere also, but have never done any of my own tests.