Comodo products are mostly half-finished. You have CIS and its powerful features, and the rest just lives off this fame. And CIS has its own problems as we are aware. Comodo don't maintain their products properly, which is a shame, but anyway, I didn't come here to bash Comodo.
I came to say that sometimes programs make changes after a reboot, or after running, so just monitoring the installation is not enough. Also, even when you use Revo or Geek or another power uninstaller, there is a chance of traces still being left behind, so it is interesting to learn how to use a registry cleaner properly. However, only do this additional step if you have confidence in your abilities to make decisions and revert them if necessary (always backup). Finally, following this be-careful-with-registry-cleaners advice, it is also sound to say that you should always review the files and registry entries that your power uninstaller wants to delete, because there is also a chance that unrelated data may be listed for deletion.
I have not made an in-depth investigation of these programs, but I did compare the uninstallers of Wise and IObit on one occasion, and I found that IObit was more thorough. However, I do not like the way it installs in the system either, so I use the PortableApps.com version (actually for both products, Wise Care has also been going in a direction I don't necessarily appreciate). Geek has that wonderful simplicity, like Revo, but they are less powerful in their free versions.