I've used Bryce at work for years... it does some really cool things. It rules when it comes to making sci-fi terrains. Getting something realistic out of it is not easy. I don't think it lends itself to AH terrain creation... Bryce's strengths lie mostly in the textures, which won't come over to AH anyway.
Yeah, and the interface is trippy... sometimes it gets in the way.
Otherwise, it is fun to play with. It's a good tool to have in your toolbox.