Couple issues, from someone who is using both.
1) Screen aspect ratio, as the other guy mentioned. Most HD format is widescreen, so Android lets you use the entire screen for watching video, without cropping. If you watch a lot of movies, this could be a factor.
2) the iPad Air 2 gets insane battery life. I charge it like twice a week and I use it daily. It is that good, and I don't know of anything on the Android side of the tablet world that can touch it.
3) The iPad will have a lot less options than Android. The OS is not much different than it was in 2007. There is no real desktop environment, no widgets or real time data... just an old slab of icons that you can't really customize, that you can manually launch one at a time... If you care about widgets and live email, message, RSS feeds, weather, music, etc... iOS will leave you wanting. It requires you to determine what you want, go find the appropriate app and manually launch them one at a time.
4) There is no user file system. Each app has it's own sandbox. If you want a file to be opened in more than one app, you need more than one copy of that file, one for each app.
5) No simple drag and drop USB functionality. An Advantage of Android is that it is universal, just plug it into a Windows, Linux or MacOS device and it pops up like a thumb drive. Drag and drop all day long, doesn't matter what type of file, no iTunes telling you that you can't transfer that file format, etc...
6) No expanded storage with Apple. You either couple up $100 more for an extra 32GB that cost apple less than $2 to include, or up your data plan and use cloud storage... Many Android devices have MicroSD slots which can be VERY useful for transporting large files, or housing an extensive multimedia library, installing extra apps, etc... Heck, with a $5 OTG cable I can just plug my 3TB external HD in to my phone or tablet and access it just like a PC would...
7) More customization with Android, if that matters to you. There is NONE on Apple devices.
8) Apple puts the absolute minimum amount of RAM into their devices as part of their "planned obsolescence" marketing strategy... I had an iPad Mini 2 Retina and had to return it, the 1GB of RAM, not seen in Android in several years, was completely inadequate. Sluggish, constant page reloads when browsing, it just didn't have enough RAM, and as a result the newer features like split screen and multitasking, wouldn't work on it... so that is how they get you to upgrade...
What the iPad has going for it is:
1) Outstanding battery life, possibly the best. Android rules that part in the phone world, but Apple has it in the tablet
2) Lots of quality apps, although both app markets have more than anyone could ever use, so that's a tie probably
3) Build quality is about as good as it gets.
4) Resale value
5) Lots of accessories...
The cons are above, but namely the limitations that the OS puts on you, no customization...
I am an Android fan, having had several crappy iPhones and leaving Apple several years back. I was very frustrated with my iPad Air 2, until I had to adjust my expectations.
It's a gloried eReader. Good for browsing, basic multimedia, email, some games, etc... It's more for entertainment. If you are a casual user and just want the basics in a solid, quality package, coupled with insanely good battery life, get the iPad.
If you are a power user, you want it to me more of a "PC experience in tablet form", the iPad is a poor choice. Stick with Android or get a MS Surface 3/4 or something that gives you all the standard PC functions, but in a nice portable format.
I like my iPad, but only if I keep it within the narrow context of what it is designed for...
Don't ask yourself what platform you want to own, and then try to figure out how to make your needs and usage patterns conform to that...
Ask yourself what you want to do, today,and in the near future, and let that dictate what platform is best suited to fill that need.
I found that coming from Android back to Apple was hard. You will be giving up a lot, most likely. Doesn't mean that it is the wrong move, but there are sacrifices to be made for that battery life, etc... Android is typically 2 years or so ahead of iOS when it comes to new features. So giving those up can be frustrating, especially when Apple obviously has the money and ability to have them, but they choose not to.