For many years now we have kept a third party disk defragment tool in our tool kit, the product was UltraDefrag.
We started with version 6 in the days when Microsoft’s built-in defrag did a pretty poor job and using the free version of UltraDefrag delivered a noticeable performance boost. Begin a free tool we could install it temporarily on clients computers when being serviced and recommend the product to customers. Many of our customers reported that they installed UltraDefrag and made a donation to the author.
UltraDefrag could also be used on server versions of Windows which was a huge benefit however when UltraDefrag upgraded to version 7 we started to be concerned with frequent lockups , hangs and force reboots on both Windows Desktop and Server operating systems. We advised everyone to stop using UltraDefrag.
UltraDefrag development stopped at version 7 and then announced version 8 would be released. After a long period of hibernation and recently version 8 was released. You will note that version 7 is still available as a free product and version 8 is now a constrained commercial product with two variations.
There is very little details as to bug fixes and no public forum to discuss issues, this is important particularly where a product could damage the file system.
So the decision comes down to do people on Windows 10 need a third party defragmentation tool?
Windows 10 now has a built-in defragmentation tool that does both defragmentation and optimisation and it does a reasonable job for traditional hard drives and trims SSD drives that would satisfy most users.
UltraDefrag 7 is free and can be used on any number of computers, however version 7 became buggy and raised enough concern to stop using and recommending it.
Windows 10 built-in defrag is install on all versions of Windows 10 desktop and server and does a reasonable job.
Conclusion
With significant improvements in Windows 10 Defrag\Optimise and more devices using SSD drives then we feel that there is no longer a need for third party defragmentation tools regardless of free or paid products. There simply is little advantage over operating system utilities.