I work in the IT industry ...............................
I would be more worried about the possibility of being traced by my phone using the GPS which is much harder to stop, even if you turn off the GPS generally its not turned off you've just turned off the interface the GPS itself is still running.
Dont believe what Apple tell you either they collect it just like everyone else no matter what the T&C's say, they have lots of clauses which contradict each other just so they are covered.
Personally I have updated to W10 as the data collection side of things doesnt bother me, I have a high security clearance so I get checked often and my search history is looked at every now and then as part of that. As I was told the first time I was checked, "If its illegal then why would you look? If its immoral why would they care?"
Phil