"those products" What products? If you are referring to the Vocola package, that does not change. It will remain a separate installation.
QMP 4 no longer supports the CronusMax Plus/Titan 1 PCPROG connection, which very few people used, but if you do, stay with QMP 3.09, or use Cronus Pro and X-Aim to drive the PCPROG port on the CronusMax Plus.
QMP itself is a single file that overwrites the previous version's file, if they are installed to the same folder. There is no clean up. As far as ViGEmBus and HIDHide go, if you already have them installed, no need to install them again. They keep themselves up to date.
If you want to keep both QMP versions, install to a different directory. The last one installed will become the default one associated with QMP files and the start menu/desktop icon shortcuts.
If you have a shortcut to QMP4.0.07, just delete it. There are no new features in this new release.