As I wrote on my second paragraph on my previous post, it's a marginal improvement, and left instructions how to do the testing. Don't have any stats as I the information I collected from my testing was only for me, nobody cared for it anyway. Probably you never took time to make any measurements or to make maintenance to hundreds of PCs over years for a living, well for you it doesn't matter, probably you're the average user/gamer and you're fine with your zero Registry maintenance and mediocre Windows Defragmentation, and yeah you haven't measure the Registry usage and it's access, and you really don't care about it and yeah the gain is minimum but you shouldn't say at all since you haven't even made the testing, and is there, little but it does exist, so affirming it's not at all impacting performance is incorrect, and BTW performance on a PC is build like this, a piece at the time at some point. Yes I have read those articles, they have truths, half-truths and jumping to conclusions too, just like you're doing it here. Just do that 1 testing, install a Backgroound Registry Monitoring access app,just to count the accesses and the amount of data modified
As for the desfragmentation, Windows file defragmentation measured by PerfectDisk and other defrasggers analysis after the fact show file is mostly good, but the way it moves the files is inefficient and a few files are not defragmented properly or at all, like folders, and system files are never optimized, Perfect Disk solves all these problems with a normal defragmentation, except the system files, moves all folders to a single location, that are defragged on offline boot mode, for a privileged disk access, and prevent a lot of Windows simple and inefficient disk write, and has a background defragmentation, but if you want to accumulate small inefficiencies and say it doesn't matter OK, it's your time