It offers more blade at the same weight and there's a better overall balance to the knife. Elmax vs S35VN is up for discussion.
This is why discussion boards can be good. Differing perspectives.
To me, the 0560 mostly delivers dead material. The .25" of extra blade is ok, but not really a difference maker when added to an already 3.5" blade. Then there's this:
Baby got BACK!
I wear large gloves. The 0550 sticks out about 1/2" from the hand when I hold it in a hammer grip. The 0560 adds another 1/2" beyond that. I have no idea why they did that. It serves no useful purpose, and actually pushes the pinky jimping and the fat part of the grip out a bit. Those parts contribute in a small way to leverage, so I don't get why ZT pushed them farther back.
Not sure how the balance of the 0560 is an improvement. If we're going to make it a big enough deal to talk about it, then I'll offer that I prefer a tasking blade to have heft slightly toward the blade rather than back toward the handle.
I totally agree about Elmax vs CPM S35VN. I have time with both, and I like both just fine.
Naturally, this entire post is hair splitting. After all, that is really what most of us do in comparison posts. When it comes down to it, we have a lot of in depth discussion about details that rarely influence user experience very much. The 0550 and 0560 are both fantastic offerings. I can't fault anyone for favoring either. It simply happens that I find the 0550 more practical, and the 0560 sexier.