In my experience, bitbucket has been extremely unreliable and creaky compared to github. I see frequent random unscheduled outages where the ssh connection won't connect, ssh won't authenticate, or hg won't respond from the other side. The web interface also caches a lot of stuff too long; I've seen it take a few minutes for its idea of "tip" to refresh after pushing new patches, and stripped revisions linger in the log view for similar amounts of time. Hopefully now that Atlassian's bought them the service quality will improve over time.