I like to ask the demonstrators how their products support review or inspection of documents and relate this to my 20-years ago experience in this domain.
Twenty years ago our Applied Research group in Honeywell-Bull (working with technology from a research group at the University of Illinois) built a working prototype that could be used for the Software Inspection process (a more formal kind of peer review) that some companies like ours were using. The essence of Inspection is that a document (or program code) is given to a small "inspection team" who in the Preparation Phase look at it and make notes. Then a meeting is called and the leader walks everyone through the document and the inspectors raise issues that they found. The team classifies these defects and attempts to determine the cause. Afterwards the author corrects the document or code and the statistics are rolled up so the organization can learn what kind of things are causing defects so they can improve their process. Although designed for software this process is useful for other things such as legal documents, marketing materials, presentations, etc.
In our system, called Scrutiny, inspectors look at the document on their computer and make annotations. Then at an appointed time they all sit at their screens, the moderator zooms his/her mouse over a portion of the document and that gets highlighted on everyone's screen along with the annotations made to that portion and the discussion ensues via the text messaging component to identify the defect and classify it. We first demoed at the CSCW Conference in the fall of 1992. We wrote a few papers - I was usually the lead author and among other places got the this one: Scrutiny: A Collaborative Inspection and Review System accepted to the European Software Engineering Conference in Garmisch-Partenkirchen.
We continued to develop it, got some people in the company to use, got a DARPA grant, and made several efforts to productize it including a possible spinoff- but large-company politics made it impossible so the idea was dead in 1995. I do point out that Network Technology was pretty crude in those days (Mosaic, the first Web Browser first appeared in 1993), so this was a pretty ambitious project.
None of the vendors that I talked to can easily support the synchronous meeting portion. Some use screen sharing which is a partial solution but no-one had the capability of allowing everyone to easily see other people's annotations (in our system this was automatic). Too bad, I still think this would be a useful function. There are some products available today - such as CodeCollaborator by SmartBear software that look like they do a pretty good job at this function but I've never seriously explored it.
(I used the Multics logo for this post - we started doing Peer Review of code in 1968, and had an electronic meeting tool, Forum which we used in the early 1980s, occasionally for peer review.)