The appeal of Seam (for me anyway)
- Annotation on the model for O/R mapping. No more hibernate XML mappings.
- Generates the DB from the model. The reverse of how Rails does it but it's still DRY so I'm happy.
- Annotations on the model for form validation. They don't seem as flexible as the Rails validations, e.g. I can't find a way to do the equivalent of validates_uniqueness_of or other complex validations using model annotations in Seam.
- Testable. Hopefully unit testing the applications will now painless enough that I can get into the habit of doing it.
- Automated builds out of the box. Comes with ant build script for common tasks.