For QE it doesn't matter which format is used, the most important thing is to have the same format for all components (such as fuse, switchyard, ...) and the same version of features in one component (such as org.fusesource.ide.core.feature, org.fusesource.ide.jmx.feature in the fuse component)

The benefit to using jgit timestamps is that you know exactly when the code was last modified, and if you look in the plugin's manifest you can see the SHA used to build the code. From that you can then find the exact commit in github.