It took me a couple days, but I slowly moved over about twenty repos from Bitbucket to Github. The biggest advantage of Github for me is that the issue tracker is much easier to use, and I now have everything in the same place.

It's a shame Github didn't improve its repo importer at the same time to also support importing issues. I was able to use a Python script that took care of that, but repeating the process on 20 repos took a while.