Ah that wonderful topic, Should I defrag my OS X disk?
This comes up often not just here and you will find that there as as many opinions on this as there are posters in on the Internet, basically an infinite number 😉
While in the past with older OS and disk technology defraging was sometimes beneficial I am of the opinion that with modern OS's and technology this is no longer required and in some cases can actually lead to a decrease in performance.
There are a few cases where defraging might be beneficial, I'm thinking of video editing where you are streaming huge amounts of data but then those files should not be on your system disk anyway.
So for me this is a none issue I don't defrag and I don't believe it is worth the time and resources so I can't give you any specific recommendations for software to do this. You could copy everything off your root drive, erase and format it, install the OS and then copy everything back. That will put things 'in order'. Remember you have to copy not clone as a clone will just put things back where they were to begin with.
If you do do this please post back both the results of Diskwarrior after the defrag and if you think it was worth the time and effort.
Remember system performance depends on a number of factors, root drive free space, the health of the drive, the amount of memory in your system matching up with the way you use the system, etc. If defraging buys you anything I would put it far down that list.
regards