I have always thought that cleaning the registry on a somewhat regular basis was supposed to be a good thing. I think that was just me buying into the hype of them to create their own justification. If anything, they've caused more problems than anything else.

Anything that removes entries from it, outside of cleaning up after an abortive software removal with a vendor generated removal tool, is something that I won't be using anymore. I'd just as soon do a clean install of the OS via a new image once a year than run the risks associated with regular use of a registry cleaning program.