I've completely converted an online community previously done is a proprietary framework to JBoss SEAM. The core functions of the site has been done within 1 week learning SEAM from scratch. I'd have to say it's by far the smoothest transitions I've had in the past.

I supposed it's not really just because of SEAM, it's the fact that all the goodies are starting to come together at this time, EJB 3 being much eaiser to deal with than its previous version known night mare plagued with repetitive code, JSF being much more mature than it used to be with many more extentions such as tomahawk and ASF, and SEAM just ties all these things together without needing to write an extra 20 XML files just to make things work.

Here is the site I've used as a pilot for my first SEAM project http://vnl-online.com

By the way. There wouldn't happen to be a good book on SEAM yet is there? The docs are great but not quite as detail as I'd like.