After a bad experience with pre-V3.0 System Cleaner (had to System Restore to get it back since uninstall didn't work) I decided to try the latest version. My platform is Win7 Home Premium 64 bit, dual core (dual thread) i3-M330, 4GB RAM, regularly patched, and used every day.
Since installing a few days ago I experienced two BSODs, something I have not seen since starting using this machine in April '10. I also saw a tremendous jump in RAM memory utilization due to the Cleaner Validator (I think that is the name) process, which would wake up and suck down vast quantities of CPU on a regular basis even when I wasn't doing anything with the product. After all that I had to uninstall it to reclaim my stable system. I appreciated the vastly improved UI and functionality of the product, but feel that it is way too invasive at a deep level in the OS to be worth my while. I was not suffering from performance issues previously, and take great care regarding privacy with other tools.
I love other Comodo products like Internet Security Premium, Easy VPN, Digital Certs, etc. The Registry Cleaner, however, just doesn't play well for me now as in the past. It seems to go over the line in providing the services it offers at the cost of system stability.
I'd love to hear any feedback from developers, other users, and smart people who might have any insight why my experience with this tool has been so abysmal.