This is good, heavy question. I think it depends on the user. On github, you might only have code - personal projects. But you might also have responses to is

This is good, heavy question. I think it depends on the user. On github, you might only have code - personal projects. But you might also have responses to issue trackers, a timeline, responses to pull requests, a commit log, documentation, etc. On SO, you have a lot of things but you'll never have the code. So if the user uses github like I do - as a git repository and nothing else - then it's probably not super worthwhile and SO is probably more useful, but if they are engaged in the github community and have active projects with multiple pull requests and keep good docs, then it's probably the more valuable resource.