Yesterday I took my phone to Apple in Scottsdale, AZ (I made the reservation a week prior) and it had about 80% charging capability, but it discharged very rapidly, making so that it needed to be charged about every 4 hours. And it was sluggish. As I have one of the really crappy 6S' (made during Sept / Oct 2015) was free after I drove 100 miles each way to the closest Apple Store. Our local Apple certified repair place recommended taking it to an Apple Store because "if the tab breaks in the replacement process a new phone is the only alternative and then it would have to be sent in anyway", and furthermore they would charge $30 labor regardless of the warranty program if I decided to use them). I arrived just before 10am when the store opened (appointment for 10am), and despite a reservation for a battery replacement, the reservation doesn't mean they had a battery, and I would have had to take the phone back when a battery for me arrived (two weeks? three?). In a wise move, since I arrived at opening the day's shipment of batteries had not yet been allocated to prior customers, Apple recognized the distance and the fact that my phone 6S qualified for a free battery (the Genius I dealt with wasn't even aware of the free battery program and I told him about it), so I was told to return in 2.5 hours to pick up my phone. Evidentally, they expect everyone to come in twice. Apple phone support had told me that 1. some stores will call to let battery replacement customers know there are no batters, though that was clearly not the plan at this store and 2. that sometimes Apple makes arrangements for loaner phones, which was going to be my meltdown strategy if they couldn't fix my phone same day.
How does this play out? Does Apple really expect people to go without their phones? I lived in Silicon Valley for thirty years and it seems that Apple thinks everyone has five Apple Stores within twenty minutes. Now, I live in Prescott, AZ. If I couldn't take a day to drive my phone to the store and wait for repair, mailing is the only option. How does that work? This is a PHONE (and for many, our only phone). For the time my phone was with Apple, I used my iPad and Google Voice; I am tech savvy. How in the world does Apple think people can give up their primary communication device for even a couple of days? I have this recurring scene where a lost hiker is trying to phone for help; but sadly has a crappy Apple battery and the battery dies (after only four hours) and the hiker dies, all because Apple didn't tell anyone their dirty little secret.
Addendum: Well, ha ha. I don't use my phone to play games very much. Just Bejeweled for a short change of pace. The game stalled and locked up all the time and i just thought "oh, crappy game. EA (a former employer of mine) must only want paying players. Well, the new battery fixed that issue. Does Apple think we will call with every little issue? App developers should be pissed. Apple's slowing of apps to protect the battery life reflected badly on them.