I had used the SOS freebie of this when it was version 3 and found it so helpful that I popped for version 4. Drive Booster has worked well on our computers, pretty close to flawlessly. We’ve had an instance or two where it has been unable to install an update, but in each case Drive Booster 4 Pro did install the update after rebooting the computer and installing each update individually (instead of all updates one right after the other automatically). I can attest that Drive Booster 4 Pro works well.
While it does make a restore point before installing each update, I do take the precaution of making a backup image of my “C” drive before installing a lot of updates via Drive Booster. So far, however, I haven’t had to revert to the back up images due to any updates installed via Drive Booster.