Hi,
I have both Z axis and XP rods.. 2 pc & 4pc.
My opinion is.. (ready to be shot down!)
The original 2pc XP, in my opinion, is better than the 4pc.
The 4pc doesn't feel as light and i prefer the casting feel of the 2pc. I say 'feel' because i dont think there is much difference in the action? Both are fast rods.
I agree its a pain for transporting and like you, this is why i went for 4pc as well.
The Z axis great but i really cannot find a single thing to say about the Z axis that makes it any better than the XP? (apart from the colour of the metal tube!.. I prefer that?!) The Z axis is still a great rod but it feels slightly heavier, less sensitive at a push, and for me, really doesnt improve on the original XP.
Whenever practical i always go back to the 2pc XP.
For practical reasons, if you have to get it in the boot, and you have to change from the 2pc XP, you will not be dissapointed in the XP 4pc or the z axis and i truly beleive its all down to whether you want a later model, different colour, etc... as i cannot find a performance reason for picking one over the other.? Lets see what the experts think.. Particularly the casting instructors?
Sorry that doesnt make it crystal clear but just sharing my thoughts