[mickdj]

"The OS will almost always be able to minimize battery usage because it has way more information than the App could or should ever have."

This is only true for standalone apps which don't share location information between people.

The OS doesn't know that one person wants to turn on the GPS on another person's phone.

I'm actually pretty pro-Apple and anti-Android (James, OP is the Android developer and I develop exclusively on Obj-C).