The short answer is, I like it even better than CPM-154... and I like CPM-154 a
lot.
Here's the
datasheet for Elmax. The chemistry isn't extreme or bizarre; it's just well-balanced and very clean.
PROS: If you've worked with other high-alloy tool/stainless steels like S30V, you won't get any nasty surprises. I find it a little more difficult to grind than plain carbon steels of course, but a little easier than CPM-3V. It doesn't seem to be real hard on drill bits. It's really clean, finishes very well and can support a very thin, keen edge. It's not terribly hard to sharpen but it does hold an edge quite well, and it has good corrosion-resistance. It's also pretty tough, especially for a stainless steel. It's still relatively new to the custom knife market, and interest in it continues to grow... that can be a selling point. I have a couple custom orders on the books right now simply because the client wants to try Elmax in a handmade knife.
CONS: It's kind of expensive, and sometimes a little hard to find in the size you want. It requires good HT and benefits from sub-zero or cryo treatment. I send mine out to Peters' for HT and cryo.