I have had a 6 Plus for 3 years, my girlfriend has a 6 as well but none of us have the issues you describe. Yes it got quite slow with iOS 11, but it's just a b

I have had a 6 Plus for 3 years, my girlfriend has a 6 as well but none of us have the issues you describe. Yes it got quite slow with iOS 11, but it's just a bit laggy at times, no long pauses that require a reboot.