One feature of it that I don't like is that Quick Clean tells you nothing before, during or afterwards about what gets deleted - just the total number of files - so if it changes anything in the registry you won't know what it's done.
In the settings on mine for Quick Clean I don't see the option for Registry Clean, but it does it anyway so maybe it's one of those things that you can't undo once it's set (which I would say is a definite bug in the program, but never mind).
