I hate that github does pull request merges with --no-ff, so what happens is that I manually pull the PR, merge it locally, and push. Github is nice enough to notice that the PR was merged, so its status is appropriately closed (if that was a fast forward, I don't think it detects rebases), but that makes me have to go out of the browser to start typing commands when I could have just clicked a button and be done with it. Essentially, it's a smoothness problem.
