The ZT is a great knife.
This is coming from someone that EDC'd one for about 6 months. And someone who doesn't have the Southard.
That being said, I would pick the Southard between the two. Both have a good steel and technically the same materials(besides the different blade steels) and features. However, the Southard appears and is very likely more EDC friendly. I prefer the smooth ti, I also prefer this because even if the knife is a brick it seems less so without the texture everywhere. The fit and finish on the 0560 is great, however, I want to vouch for the quality of Spyderco's Taichung knives. They have the fit and finish and quality of a knife double the price. On top of the excellent designs and materials they use, I have not had a Taichung Spyderco that wasn't perfect or at least close to it.
The Southard seems more EDC friendly and like a better EDC. The ZT 0560 ended up being too bulky and overhyped for what it was to me. Don't get me wrong though, the ZT 0560 is a great beast of a knife that can handle a little bit of everything. But if I were choosing, I would go for the Southard.
However, you need to make your own opinions and pick the one you think suits you best. =]