The way I structure my commits, it is usually (but not always) easier and more reliable for me to replay my commits one at a time on top of the main branch and see how each relatively small change needs to be adapted in isolation--running the full test suite at each step to verify that my changes were correct--than to be presented with a slew of changes all at once that result from marrying all of my changes with all of the changes made to the main branch at once. So I generally start by attempting a rebase and fall back to a merge if that ends up creating more problems than it solves.