Yep, if you want a rather short description of the difference, what you say is quite fitting.
I loved the 9143 when it came despite it was way softer than what I (and other Scandinavians) mostly used at that time. The action is deep down, 3/4 - full action. In short it was a cool rod, with a couple different "gears" so it handled quite light floating or sink tip line work casting with short strokes and off the tip, as well as heavier sinking lines using more of the rod force - am talking Scandi now. Actually this is probably the rod I have used the most over the regular 15' rod common for early season sinking line work here. I pensioned my 9143 when the cork was worn down in 2012 having used it tremenduosly much since 2007. It became a cult like rod in our circles, a love it or hate it rod, looking back I would say the tip could have been somewhat more firm... but that would have made a different rod.
I replaced it with a ONE 9140, which I would say is more a 1/2 - 3/4 action. It is a lighter, faster, more responsive rod typical for last generation graphite rods. It is not as "extreme" as the z-axis and I guess overall easier to like. While I used the z-axis mostly with Scandi heads, I use the ONE also with Skagit and hybrid lines such as Nextcast Salarfinder and it excels on all. When you line it up and cast it it will feel deeper than when you just shake it in a shop... Both are great rods yes but different!