I started out with O&O. It was good, but not the best. Then I moved to Diskeeper. I liked Diskeeper and it did its job better than O&O. Eventually my liscence ran out and I wanted something new. I moved to PerfectDisk. Its by far the best defrag tool I have ever used. It allows smart placement of your files, you can compress the unused space and defrag what you have. It works excellent. It also has boot time defragging which helps alot with the MFT.