The answer to this question lies in what you intend to work on. Many users prefer to use wired options if they are planning to work on a project for multiple days at a time. Wired options will not lose speed and strength as you work, and a dead battery is going to leave you stranded in the middle of a job until you are able to fully recharge. The downside to wired options is that you are limited by the length of your cord (or extension cord) and that cord can also get in the way of your work- especially if you are working in tight spaces. Battery options leave the user free and untethered from an electrical outlet, but they will run the risk of losing a little bit of speed as the battery life drains. If you like the idea of a battery powered unit, we suggest buying an extra battery. That way, when your battery dies, you will have another one waiting in the wings.