How much more storage than iOS 7 does iOS 8 ACTUALLY use up? I have read so many reports about iOS 8 installation storage requirements that I've lost count, and none of them even answer this very basic question.

“The download is 1.2 Gb… the free space requirement for the install is 5 Gb…” etc... But honestly, who cares? We get the space back after it’s done. It's a one time requirement.

What's ultimately of interest when I install iOS 8 on my iPhone 5 is: how much space will I never get back?
The Ars Technica iOS 8 Thoroughly Reviewed article pegs it at 600MB difference on the iPhone 5.


DEVICE  SPACE AVAILABLE    (IOS 7.1.2)  SPACE AVAILABLE (IOS 8.0 GM)
32GB    iPhone 4S (AT&T)    27.4GB      26.6GB
32GB    iPhone 5 (VZW)      27.3GB      26.7GB
32GB    iPhone 5C (AT&T)    27.2GB      26.5GB
64GB    iPhone 5S (AT&T)    56.0GB      55.1GB