We use a server-based document to allow customers to edit our customized publications. Any customer representative or group of customer representatives can edit a publication at the same time using only Adobe Reader. The editor makes a group of changes, comments, or suggestions and clicks a box titled "Publish Changes". The changes then appear on the new saved review document and all other reviewers can see the changes.
We have watched debates rage in the comments pane with a supervisor finally settling the argument. Our customers embrace this process and we love it because we can see everyone's comments and edits in one ducument, and every reviewer sees everyone elses comments and edits. Our procedure is the most effective and efficient we've seen.
This screen shot shows what our server-based review environment looks like. Note the discussion happening in the comment section.