City Engine and Unity iPhone games

Has anyone used city engine to create a city for an iPhone game? I love the tool, but I’m a little concerned that even at a low level of detail that the thing will just not perform well.

If you’ve done it, what has your experience? Any tips or tricks to optimize performance?

Thanks,
Pat

Do you know the link for their website?

http://www.procedural.com/cityengine/features.html