I tried a ZT0550 back when they first came out and ended up selling it promising myself I'd pick one up again some day. Since they were discontinued, I thought I'd better pick one up since it could be my last chance to get a new in the box 0550 at a decent price. I got one (and a backup) and couldn't be happier. I can't think of a better general hard use folder. It's simple, reliable and made from premium materials (S35VN steel, phosphor bronze washers, titanium framelock!) by people who know what they're doing. It performs equally well slicing through packaging and rope or carving wood. The deep carry pocket clip works great, and while the knife is wide it isn't too bad in the pocket. It's an incredible value at $130-200 that they're closing out at.
I've also had a chance to put my 0180 through its paces. I was very excited to get one of these, and received mine immediately after they were released. The handle, with it's finger cut outs, is extremely secure in use, but it is not restrictive to certain grips. I like the relief cut into the G10 for the jimping at the top of the blade. I've cut, carved, and batoned my 0180 and it's been great. I'm not sure about the steel yet, as I had trouble with the factory edge (no surprise, I always withhold judgement on a steel until the factory edge has been cleaned up) chipping a bit but I haven't had any problems since I cleaned the edge up. I love clip points, and this one is very well done. The blade is narrow, like a good utility or bushcraft knife. The sheath that came with the 0180 was not deep enough for the blade (so the knife sat crooked and barely fit into the sheath) so I made my own out of "urban digital camo" kydex. The profile of the G10 scales make it very simple to get great retention from a kydex sheath, if done right no kydex touches the blade, only grabbing the G10. It is a shorter blade so it doesn't take up much space at all on my belt, and the large TekLok is very secure. The only thing that the 0180 is bad at is food preparation and slicing through thick material.
Both knives have ZT's awesome blackwash finish
I've been anything but gentle on the 0180 and it is very hard to find any sign of wear in the finish.
Here's the ZT 0550BW and 0180:

Another picture of the sheath I made:

I've also had a chance to put my 0180 through its paces. I was very excited to get one of these, and received mine immediately after they were released. The handle, with it's finger cut outs, is extremely secure in use, but it is not restrictive to certain grips. I like the relief cut into the G10 for the jimping at the top of the blade. I've cut, carved, and batoned my 0180 and it's been great. I'm not sure about the steel yet, as I had trouble with the factory edge (no surprise, I always withhold judgement on a steel until the factory edge has been cleaned up) chipping a bit but I haven't had any problems since I cleaned the edge up. I love clip points, and this one is very well done. The blade is narrow, like a good utility or bushcraft knife. The sheath that came with the 0180 was not deep enough for the blade (so the knife sat crooked and barely fit into the sheath) so I made my own out of "urban digital camo" kydex. The profile of the G10 scales make it very simple to get great retention from a kydex sheath, if done right no kydex touches the blade, only grabbing the G10. It is a shorter blade so it doesn't take up much space at all on my belt, and the large TekLok is very secure. The only thing that the 0180 is bad at is food preparation and slicing through thick material.
Both knives have ZT's awesome blackwash finish
Here's the ZT 0550BW and 0180:

Another picture of the sheath I made:
