For me, it's about 50% for each. I often create a branch just to snapshot the current state of the branch before squashing or rebasing. When I do this, I do not checkout the new branch, and in fact, most likely I will never check it out.

A common mistake people make when bitching about Git, is assuming that their workflow is the only workflow. Git supports a multitude of different workflows, and that fact is both a strength and a weakness.