When I've done cliff/ledge stuff, I tend to use a combination of lots of small terrains, symm lattices and rocks to get the shapes I'm after. Essentially I just build up what I want out of all these small elements - this works in bryce, so I reckon it will work fine in Vue when I get around to making a cavern or two later on. Its a lot of work to build things up this way, but it gives the best results/greatest control of any technique that I've tried.

Dreams are just nightmares on prozac...
Digital WasteLanD