Very good for rapid map creation with randomization + some light touchup. I was able to get effective maps into the VTT in under ten minutes, five if I'm in a hurry.
The one major flaw is that there's no way to change the size of the UI or text in the UI, which makes it difficult to use for some people (I am some people) if you have a larger monitor. Its not completely unusable, but the tiny text size is a bit of a pain, and some people might find it worse.