I've held finely-made, beautiful Azo prints in my hand in which the guy sitting next to me claims to see a 3-D effect in it. I look at the print and I don't see it. It looks like any other well made print on a good B&W paper to me, but nothing that I see as being three dimensional.
I'm skeptical of this so-called "3-D" effect that people report that Azo has. Perhaps it's an optical illusion that some peoples brains process, and others can't.
Let me hear your anecdotal stories and convince me one way or the other.