We – eCentres.net - are using, with a lot of problem of daily configuration and setting, rather than 60 modules and three subdomains.
The collaborative community – working in European research projects - now has a basecamp of 3000 users – biannual newsletters - and 300 collaborative participants, who needs mainly: a join calendar of events; the work-groups and all the rest of traditional modules associated.
In addition, the basic forum and messaging and all the modules - it is needed more - of users, communities and profiles, usermap, userlist, search users, directory, etc
On the other hand the modules of sharing files and documents - not absolutely solved - maybe with the drupal-ftp module...
And finally and a lot important the media sections, podcasts, image gallery and video section - not well solved.
The next steps is to integrate the donations, fees and commercial solutions and multichannel communication as SMS, and skype and IRC solutions and webminars.
Any other simple or partially CWE in my honest opinion are not really sustainable.
1More