I have almost a dozen Anza's of various sizes and shapes.
My general feeling is that you get a lot of knife for the cost. They're fairly easy to sharpen, and they hold a decent edge. I would estimate them to be a touch on the softer side (compared to the high Rc hardness on higher end models), but definitely hard enough to work with. As a completely unscientific gut guess, I'd say mid-to-upper 50's (56-58).
They're not stainless (nor are they claimed to be), so if you want a really bright shiny polished knife, an Anza isn't the right choice. However, if you don't mind a knife that looks a little rougher, darker, and well used, Anza might be the way to go. I wipe mine down about every 2-3 weeks with a Tuf-Cloth, and there's not a bit of rust on them. I only have one (older one that's seen some really heavy use) that did get a bit of real rust on it, but a little naval jelly and steel wool took it off in a hurry (even in the file grooves).
I haven't had any problems with durability or brittleness, myself. I've beat up a couple of them pretty rough, and so far no issue. They tend to be pretty thick-spined, too, which will toughen them up some. While they don't have the thinnest profile around, they generally aren't too bad. They're hollow ground in order to provide a reasonable edge, while retaining the thick spine.
Again my general feeling is that Anza's represent a very good value. You can find a better knife out there, and you can find a cheaper knife out there, but you'd be very hard pressed to find a better knife for cheaper. Anyone look for a fixed blade in the under $100 range would be a fool not to at least give them a look.
Oh, and Smaller ones can make great EDC's. I have an Anza TW, which is about 4" overall with a 1 5/8" blade that I wear on my belt and is part of my EDC. It's small and non-threatening size make it easy to carry and use at work (and elsewhere) without anyone raising a fuss.
I actually ordered a new TW just recently, and through a mistake on the retailer's part, I ended up "buying" an extra. Since that time, I've been thinking about what to do with it, and I've been leaning towards putting it up as a pass around here.
In fact, I might put it out there as a pass around, with an incentive for good reviews that the person who provides the best review for it gets to keep the knife.
Is that something people would be interested in?