They are lucky. Some people who are used to seeing higher frame rates and random drops like gamers, are people who will see these issues ALL the time as they ARE THERE! Just more average people don't see them. This aggravates the person who sees the issues all the time, and it aggravates the person who doesn't because they think the one complaining is a snob, when they simply have more sensitive eyes when it comes to frame rate.
About frame rate and refresh rate:
It definitely has it's issues. Watch this video in 60FPS and if you still don't see it, you are another person who simply has less sensitive eyes. Not a bad thing, it's a good thing for you because you don't have to get annoyed so much when using your phone lol. Maybe you just don't use the things that cause the FPS issues, like what's in the video below.
My iPad mini 2 is the same as your iPad Air hardware wise, and for me, it is definitely the contrary to what you said. Everything is so much more sluggish when compared to iOS 8, opening apps, spotlight, app switcher, tons of stuff. Maybe you just don't use spotlight or the app switcher which cause such awful frame drops? Because I don't see how anybody can simply be fine with 10FPS animations in the app switcher. My iPad mini 2 on iOS 9.2b3 is worse off than the iPhone 5 on iOS 9.2b3 in terms of UI smoothness.
I definitely have, you aren't alone. I've seen hiccups on the 6S, there are others out there, trust me!
This person has clean installed their phone 3 times and have been using heir phone for awhile. Indexing isn't going to last for weeks or months.
We don't have a high bar for perfection, we just seemingly see issues so much more easily than other people. Seeing these little things all the time in daily use gets very irritating.
The 5S control center apparently is appalling at times, and it's kinda iffy on my 6 as well. I've noticed small CC issues on the 6S as well that aren't even there on the iPhone 5 due to metal. Everything so far has issues with iOS 9.
That's really sad considering how powerful the Air 2 is and the fact that it's the latest device you can buy from Apple.
These aren't mine, but they're informative to say the least. Make sure to watch in 60FPS if you can.
http://youtu.be/YCWZ_kWTB9w
I'm running 9.2b3 on my iPhone 6 and iPad mini 2. It's been better in every single way compared to iOS 9.1, but it still is not there yet. Spotlight and app switcher both still drop down to 20-30 FPS at times on my iPad mini 2 if I don't have reduce motion and or reduce transparency enabled. .1, .2, .3 etc betas usually aren't problematic. .0 beta is what generally causes serious issues. I've compared the 5 and 6S and I've seen issues on the 6S that aren't there on the 5 due to metal. The 6S plus probably has more noticeable issues.