I'm not an expert and so I write from the experience of a user who just needs stuff to work as advertised. Others at this site can provide more technical views for you.
I have used DiskWarrior since it was released several years ago and recommend it highly. DW has never failed to fix a damaged directory and, on more than one occasion, it has recovered drives that I thought for sure were doomed. It is very simple to use. You can find a review for DiskWarrior
here .
I have also owned TechTool but found that my needs were taken care of by Disk Warrior, with the exception of defragmentation. However, I also found that defragmentation didn't seem to be an issue and stopped doing it a few years ago. With the upgrade to Pro 6 I decided to go through a defrag but can't say it made any difference. TechTool has an eDrive feature that I've never used as I repair from a backup drive. You can find a review for TechTool
here .
MacKeeper? I've never heard anything except bad stories about that product.
