I used to clone a backup regularly using Carbon Copy Cloner from Mike Bombich, however, when Disk Utility started to encompass the same capability natively (using the 'Restore' feature) I haven't gone third party to make a clone for a REALLY long time. That 'one trick pony' is still the go to utility for directory damage, but barring catastrophic external events, I haven't seen nearly the frequency or intensity of damaged directories that used to be almost routine.and the native Disk Utility has been able to repair nearly all that I've seen in the past two years. Still at v4.4 although v5 has been out for a while. I bought an e-download of DiskWarrior a couple years ago to address a critical failure on my Mother-in-law's iMac when a power outage took out her directory.haven't really needed to use it since. Today, I find myself delaying upgrades due to not having used the (then current) v7 that I've had since it came out.finally, if only to support the manufacturer, and 'just in case' my El Capitan installed base shows a need, I upgraded to v8 just last week. I used to employ it routinely to resolve minor (to major) issues on my own and many other Mac's in my circle. I'm pretty much a plank owner in the TechTool Pro world, having owned almost every version since inception.

Techtool pro 8.0.3