Yes, you can still use the basic git features, and github doesn't break them. The problem is that instead of turning Git into a Fossil++, we're relying solely on Github's tooling around git. Yes, it's easier to have a centralized location that doesn't require synchronization for tickets and reviews, but when you have to move off github, you cannot really export all the history properly without losing some details, so I firmly believe we have to make more of the git story distributed. Those features can be used by github in a friendly web interface, but like the git push and fetch model, it should exist in git itself. That way, it really won't matter where users make contributions, and it will solve the Phabricator vs github dilemma for big projects, plus allow for full archiving and porting of the data. Once your tickets and diff reviews are part of the git repository, you get features that enhance the user experience. I believe git-appraisal is using git's notes feature, and that's a good way to avoid extending the data model.