Thanks for your help. I see that the program I was using, Ridnacs, wasn't providing me with useful HD info.
As I hate to have my data files mixes with my OS, I want to move my iPhone back up to another drive. Apple doesn't make this easy as there is no way to easily change the back up location.
Any thought about this approach? https://sihuwa.wordpress.com/2010/11...on-on-windows/
That would reduce my App Data to about 7.5 GBs. Is that reasonable?