EMF Diff/Merge obtained the "Most innovative project/feature" award at EclipseCon World 2013. It is a young project whose usage is spreading.
The forum, bugzilla and Gerrit show activity by different people and organizations. In particular, several Gerrit pull requests have been submitted by people external to the project.
Questions on the forum arise on a regular basis, some of them receiving significant attention: the thread with the highest number of views has a total of almost 14,000 views.