I have an M16-13Z, and I love it. It's a good way to get to know someone better; flick it and they invariably want to see it. Of course, I wouldn't recommend doing that around sheeple, but since I don't, I haven't had problems.
The knife itself is well-made. I remember a few people here (Razor, for one) saying they had to lube the pivots before it would flick right, but I haven't had to do that at all. The lockup is solid and nothing is loose. I did lose the middle pocket clip screw a while back, but I tightened the others with Loctite and they are still good to go. The edge holding ability isn't fantastic, but it does take an edge well, so it's easy to sharpen.
I recommend you buy the knife; I'd personally go for the spear point half se , but that's just me.
Asha'man