Hi aledwar,
There is also usually no need to
"optimize" or defrag in X
If you are doing a lot video edit and need to defrag IMO the best way is to clone your entire drive to another drive, erase it and clone back. Clean as a whistle with no fragmentation.
Never use Norton.
TechToolPro 4.0.5 can defragment but again why use a process that attempts to piece together thousands of file fragments with the possibly of a fatal error?
If you are not doing that type of "heavy lifting" with your Mac, leave it alone and let it take care of itself.