The OP is a lefty, and right hand frame locks aren't lefty friendly like the Axis.
KAI USA (parent company of ZT and Kershaw) is only using CPM 154 on the Kershaw Launch line of auto openers. They're using better steels like CPM S35VN, Uddeholm Elmax, and CTS 204P on the ZT line.
CPM 154 is just 154CM made using the Crucible's powder metal technology (hence the CPM prefix) rather than conventional ingot or vaccum melting. Crucible's own literature shows that the advantage of the CPM process over conventional 154CM is increased toughness and improved grindability. Wear resistance is the same.
CPM 154CM is inferior in most aspects to CPM S30V as a cutlery steel given equal quality heat treats for each. S30V has equal toughness to and better wear resistance than CPM 154 with only a slight decrease in grindability. Likewise, CPM S35VN - itself an improved version of S30V - is tougher than S30V, has equal wear resistance to S30V, and is more grindable than S30V. Hence, CPM S35VN is superior to CPM 154. The only area where CPM 154 has an advantage is that it's slightly easier to heat treat. That information is straight from Crucible's own data sheets, who's the manufacturer of all three of those steels.
Elmax is a different animal. It's a powder metal process steel made by the Uddeholm side of BU Corp (Bohler-Uddeholm Corporation), so we don't have data sheets from the same manufacturer as a head to head comparison. However, we do have info from knife makers and steel suppliers. What we know is that Elmax is incredibly tough, incredibly wear resistant, and very highly corrosion resistant; but it's one of the most difficult to grind and heat treat of the common used cutlery alloys.
So, if you want an extremely tough knife that's highly corrosion resistant and you don't mind it being rather time consuming to sharpen is Elmax is a great choice. If you're okay with lower toughness, slightly better edge retention, and increased ease of sharpenability M390/20CV/204P is the better option. If you're willing to give up that toughness and also lose a little more edge retention for even easier sharpening then S35VN is a great choice. Or if you were an early adopter of S30V and want a steel with similar heat treat process but improved machinability then S35VN is your steel. If you're a manufacturer who has a great 154CM heat treat process in place and you want improved toughness and machinabilty and only want to make minor tweaks at most to your existing HT process then CPM 154 is your steel. If you're okay giving up a little toughness and a little bit of edge retention to S30V/S35VN to get easier sharpening and an easier heat treat, then again CPM 154 is your steel.
As all of the above illustrates, we have to be very careful saying any one steel is better than another in a broad general sense. We have to define better in which ways.
