I would like to know that too very much. I want to see if any mid size+ projects out there that have any problem with the conversation stuffs, and I do have problems with the long conversations 'cuase my app requires very complex layout like tree, tab blah. However, I know the CMS project called Nuxeo.com that uses some of Seam features but MAY not using the @Begin, @End ... a whole lot, I guess. Check out this link for example (http://lists.nuxeo.com/pipermail/ecm-checkins/2006-October/000255.html)
Anybody out there want to share please?