The biggest ordeal is the time it will take for the system to run its initial updating process prior to the point when you can start reinstalling the sim.
You are looking at, mainly, a time investment waiting on downloads. Depending on which version of the sim and what Marketplace content you wish to install, that will determine your download time.
Your Logbook, controller profiles, Bush Trip progress and few lesser sim settings are saved in your cloud-based save, so that will be restored automatically — unless you decide to make the decision to completely erase your save, which is a separate step to resetting the Xbox.