I just went through the same decision process myself...
I had the iPhone3 and 3G, but was tired of the small screen and the very limited features back then... there was also the issue of it being on AT&T and getting 8-10 dropped calls per day(tried 3 different iPhones), regardless of where I was or signal strength... I finally moved to Verizon and went to Android. First couple phones were decent, but from 2012 on, Apple couldn't hold a candle to what was available with Android. More options, better phones with nicer screens and useful features that Apple fans wanted, but Mr Jobs decided that they should have to wait a couple years for... And with Android having 82% of the global market, and Apple now going to larger screens and adopting most of the Android features from 2 years ago, they obviously see the light and are trying to catch up.
That said, I assumed that the same was true for the tablet world. I had an original Nexus 7, and then decided to get a Windows Tablet... Nice enough, ran full windows and I could plug it into my Ducati's ECU to program and diagnose the bike, etc... But even with the Win 8.1 update, you just never feel like it was really meant for touch screens. It's this weird in between feel that doesn't cater to either mode of use as well as it could or should.
So this time around I read up a lot, went and played with different devices and decided to leave Windows and go back to an Android tablet. I considered the Galaxy S series and I was also intrigued by the NVidia Shield tablet running their crazy Tegra K1 SoC... fastest mobile graphics processor that you can buy in a tablet. Plays near desktop quality games, lots of cool features, console mode, front facing speakers... a solid tablet and for gaming, nothing can touch it. You aren't playing Half Life 2 on another other tab, that's for sure...
So I went back and forth between the Galaxy S 8.4 and the Shield. The Galaxy has the best screen I have ever seen on a tablet. It's amazing. But the battery life wasn't stellar and the Shield was faster and $100 cheaper, and offers more in the way of accessories and options, HDMI port, console mode, game pad controller, built in stylus, etc...
Got it home, and it was ok. It is certainly fast, but in upgrading to Lollipop it made the tablet buggy and there is no way to roll it back unless you want to void the warranty and root it, etc... To have to do that on a brand new $300 tablet, just to get it to work properly, seemed like BS to me. Tried tons of things to fix it, but just couldn't get it to not be laggy at times. I upgraded my Note 4 to Lollipop, and it made one of the best phones ever made, even better. But not so on the tablet...
So I went back and looked at the Mini 2 Retina... couple bucks more for the 32gb version, and you are giving up some things, make no mistake... 4:3 screen less ideal for movies... no front speakers... Limited storage, having to deal with iTunes, so not as easy as an Android tablet that can just plug into any USB port and drag and drop whatever you want to it or the SD card like a thumb drive... No HDMI port, non-standard proprietary plug that Apple insists on using just to increase revenue streams... No widgets or true interactive UI... just a slab with icons scattered about, no real multitasking or real time data widgets...
So in a lot of ways, the iPad is way behind the times, mainly because iOS is a couple years behind the curve.
However, the iPad looks amazing. The built quality is probably the best out there. Besides the crude UI and lack of widgets, it is simple and elegant. It is fast, smooth and seamless... It just plain WORKS for all of your basic browsing, email, media consumption and lite gaming needs. It's a fantastic tablet.
Super screen and performanance, and about as big as you want while still being able to palm it in one hand. Despite the lack of front facing stereo speakers, the sound is loud and excellent quality. Yeah, it doesn't have an HDMI port, but there's an iPad version of Chromecast...
The iOS version of Microsoft Office is much better than the Android one currently...
As for the selection of apps, both have so many apps that it's pretty much irrelevant. With Android dominating the planet, there really isn't anything on iOS than there isn't an Android version of.
I wouldn't trade my Android phones for anything from Apple. Apple still has a lot of catching up to do in several areas... But as far as tablets go, I don't feel that Android is as far along in maturity as their phones are.
Here I feel, Apple still has the edge. They are not perfect or without limitations, but for general purpose work, I don't regret returning my Shield tablet and picking up a Mini2 Retina. Yeah, it isn't as feature packed as the Android tablets, but in this price range, it's a higher quality, more refined product...