I purchased my 64GB iPhone SE in March this year. In November, it started having battery issues. When the battery dropped below ~20%, the level meter would start dropping extremely fast (like 1% every 2-3 minutes while the screen is on).
Also, when the level got down into the ~5% range the phone would become unusably slow, which made no sense to me at the time, but now I think we all know why.
After several complete discharge/recharge cycles, this behavior has improved somewhat, but the battery life still seems to be lacking and the reported discharge rate is not at all linear. Unfortunately the phone is now "good enough" that it's hard to justify returning it. Maybe I still will (because I'm running out of warranty), but I have some questions:
1) Will Apple reject it if the battery is only iffy and not unambiguously messed up?
2) Will I get my phone back, or will they send me a refurb? This is a big deal to me because my phone has a flawless screen, and it's the older, superior part. I tried to replace this phone with a 128GB version when that came out, but the newer unit had a noticeably inferior LCD panel (worse blacks and colors), and a minor defect. I have also bought two 32GB SEs for my parents and both of them had the inferior panel and major backlight bleed defects, so I really want to hold onto my unit.

