Seriously I jumped in on this deal making Best Buy price match Staples and trading a whole bunch of junk working 2-4 year old tablets for 50 dollar gift cards.
Anyhow Got a 16gb wifi space gray Air 2. for 250 bucks. First problem, blue shaded line around borders of screen for some reason maybe due to the no air gap displays. Second problem, in Portrait half of screen was yellow warm tint from center to left, then from center to right normal cool blue white. THIRD problem the speakers sound literally like crap and vibrate and shake the whole device in your hand like its hollowed out (yeah yeah apple designed it this way like idiots). The one I got was a newer manufactured one with IOS 8.4 on it. So went back in and exchanged it, Second one same dam issues and it was older with 8.3 on it although speaker vibration was not as bad as the first one but volume was lower. (returned it)
Compared to my Air 1 with what I would call an almost perfect even white screen with good color gamut actually a little too good, the speakers sound so much better, get loud and do not vibrate at all. Also I got my Air 1 a month ago for 324.00 out the door. It has the biggest battery apple ever put in a tablet. I must of got a magic battery because I constantly through full charges from 1 percent to 100 over and over, get anywhere from 13-15 hours with heavy game playing with auto brightness for screen. I mostly use it indoors and I live in Washington where not much sun so auto brightness stays between 10-40 percent. 15 HOURS for playing games such as buggy blitz, trials frontier, the new dungeon boss game, pocket tanks, and 5 other cool games. I also am on it just as much for heavy web browsing. EVER since I got this AIR 1 WITH THE MAGIC BATTERY LIFE I have not turned on my PC at all in the last month. All of my free to play PC games quality went down the gutter and with all the hackers and cheaters, there is no point anymore to play games on PC. My kids are always on the PS4....
So literally because of the performance, better app selection and pretty graphics/performance optimizations to all my favorite things to do on a tablet, MY AIR1 is what I do constantly every day for many hours to include music, movies and everything in bed. I am also a disabled combat veteran falling apart day by day internally and mentally. So my new thing to do is all of my games on my Air 1. Yes its BIG and kind of heavy, but nothing compared to my old NOOK HD+ tablet that would only get 7-8 hours browsing internet only or 5-6 hours of gaming and the performance sucked!
Then I was stupid and bought a mini 2 on sale for cheap. I can get 11-13 hours gaming and browsing on it although after the first initial full charges the battery is not doing that great, unfortunately it does not have a "MAGIC" battery. I was stupid and put IOS9 GM on it and it turned it into a slow laggy, glitchy, hitching, device with delays in loading things and animations. Also it lost an hour or two of battery life. So I quickly reverted back to a clean install of IOS 8.4.1 and now its rocking again and just as quick and smooth as my Air 1 using IOS 8.2.
I just recently bought a mini 4 and I do love the form factor, less weight, screen quality and new color gamut, and the faster a8 chip with 2gb of ram which makes applications load instant and fly when being used. With that being said though and IOS9 issues, After my first complete discharge to shutoff and then full charge to 100 percent, With not much gaming and a lot of web browsing and picture taking and editing and installing all of my apps manually and getting it all the way I want it, the battery might not be cutting it. I have auto brightness on, its a gold 16gb wifi model and I do not know if its the new auto brightness sensor or a glitch in IOS9 but it is always adjusting brightness at the slightest environmental ambient adjustment. What I mean is if there is any light change at all where you are using the mini 4, brightness goes up to super bright, or all of a sudden if its dark, it drops to dark mode and this happens quickly and constantly which is way different than IOS8 and the mini 2/Air 1 sensor. When brightness adjusts on those on auto mode it is slow to change and only goes up if the environment brightens. If the environment dims the mini2/Air 1 and IOS8 does not adjust brightness unless you turn off the screen and back on. In other words I think thats killing battery life on the Mini 4.
The mini 4 is way better than the Air 2 and all of its problems except my longest usage so far is 10 hours and 25 minutes. Like I said that was with not much gaming, but a lot of web surfing, multi tasking, PIP mode, IOS9 stuff, installing apps and trying everything out. Also it has different wifi chipset for AC speeds so that could make a difference. I think the new auto brightness feature and sensor is also killing it by jumping up and down so much and so instantly. The new screen gets super bright so it drains the battery and of course it is way better than the mini 2 screen. Also speakers are louder and has higher MP camera and such.
IOS9 probably is not helping the battery on the new mini 4.
Anyways wanted to drop my two cents in. The Air 2 is a good deal if you get one with a dam good even brightness screen with no yellowing or blueish lines around borders of screen on edges and one that is a solid color across the entire display. YOU WILL NOT find an Ipad Air 2 with speakers that do not VIBRATE. You either get one that does it super crazy, or one that does it, but mildly. Yes the Air 2 will getter better screen on time and if it had IOS 8.4.1 or lower, well battery life will be better compared to IOS9. Maybe its all the new features that are enabled on the Mini 4 killing the battery off when being used. I did play beach buggy blitz full screen with 10% fps drop while watching a movie that was from youtube embedded in a webpage that I put in PIP mode. That was nifty.
Also one good thing about NEW mini 4, IOS9 and Safari, web browsing is super smooth, instant, and fast. I loaded up the verge website, on my fast wifi/inet connection. Once it was loaded I could scroll so fast and smooth it would make you sick if you suffer from motion sickness. IT IS literally faster than 60fps when scrolling quickly down long web pages in Portrait or Landscape. ITS AWESOME!
Anyhow good luck out there fellow Apple fans!