1. Gobby is a peer-to-peer networked application and so your application is both a server and a client. This kind of networking does not play well between corporate and ISP firewalls. The only way we were able to communicate was to have three instances of Gobby running: One for me, One for Evans, and one running on my home Linux box acting as a server. And even then, Evans needed to ssh tunnel to the Linux box. To effectively use Gobby in a WAN much consideration needs to be given to network connectivity.
2. As anticipated, Gobby's document management is very weak. The documents are listed alphabetically with no meta-data about ownership, modification time, directory path, revision number, etc. I also found the floating document list to get in the way more time than not.
3. When Evans and I were discussing our first document Evans asked if I was seeing his highlighting. I was not. We both assumed that not only would you see other's changes but you would also see other's highlighting. This is a good example of not knowing what you want until to actually trial your tools.
4. Gobby knows almost nothing about the documents it is presenting and editing. It does highlight the syntax of the document based to the document's file name extension. However, our experience with IDEs is that we want really good navigation between source code elements. For example, with Java source code we want, at a minimum, 1) class name to definition source file, 2) method name use to definition location in source file, and 3) method name definition to locations of use.
5. Gooby has a instant-messaging feature but we used Skype's voice chat. Gobby as an extension to Skype would be more useful.
Overall, Gobby has too many network connectivity issues and not enough document navigation features. If Gobby were to be implemented today then it should be a web application built using the Etherpad <http://etherpad.com/> and Bespin <https://bespin.mozillalabs.com/> toolkits with a little of the Nautilus file manager <http://live.gnome.org/Nautilus>.
A tool for informal review of a tree of documents is needed. (As opposed to a set of patches for which there are great tools. For example, Rietveld <http://codereview.appspot.com/>.) So, I will keep looking. Tell me if you find something good.