Its in java - therefore the UI sucks. I made it as good as I could without obsessing over it. And it only works with postgres. I outputs EOModel files which are useful with webobjects and GLORP.
It saves me a lot of time though.
Cayenne comes with a modeling tool too - both of these tools are designed to allow ORM, but the models they produce tends to be useful for other things - it captures both the logical and physical database design for instance.