First off, I love CCleaner. I have been using it for years and never had any problems. I recommend it to my friends who need an easy way to clean up their computers.
The Wipe Free Space feature is a great addition I use, but I don't think it needs to run every time CCleaner does its magic. I'd like to see the wipe free space option modified so that it's active for just that one cleaning session. After the free space is wiped, the option goes back to being inactive. That way I don't have to remember to disable it before I forget and wonder why CCleaner is taking so long to clean my computer.
M