> I can just turn everything on, change the address, then turn it all off again

You can't - or, rather, I can't. It may be a problem that only affects me, I haven't talked to other people about it, but that was exactly my thinking a few months ago. So I activated location services, changed my home address to my new address, checked that it was set right, and disabled it again. And whoops, it's my old address again.

They might've fixed that in the mean time, I haven't checked it recently, I've just given up on using maps.