When looking for the best orbital buffer, size is one of the most important factors to consider. The right size will depend on your specific needs and what kind of job you’re trying to do. For small jobs like waxing a car or polishing chrome, a 5 – 6 inch buffer should be more than enough. However, if you plan on using it for larger areas like floors or boats then an 8-9 inch buffer would be ideal as it has greater reach and can cover more surface area in less time. It’s also worth considering how powerful your machine is; smaller buffers are usually easier to maneuver but may not have the necessary power for tough jobs which could mean slower progress times. Ultimately, when choosing an orbital buffer size ensure that it fits both your needs and budget so that you don't end up with something too big or too small for the task at hand!