I have tried them (well, one) but didn't persevere. I wanted to see if the alphas produced by ZB could be used as terrain height maps. It occurred to me that it might be easier and give better results to make these maps in ZB rather than Photoshop, since you could see the 3D effect during model sculpting.

It did work, but I couldn't say the results were any better! I haven't used these maps actually as displacement maps, but I can't see why they wouldn't work.

(Later) - just tried it on a sphere, works fine.

Steve