I had a Samsung Galaxy 10 for a year, but when the iPad Mini came out, I sold the Galaxy and got the mini. I LOVE it!! Perfect size for my purse and no problems viewing the screen, etc. Since I have had a Mac for 2 years, and also just got an iPhone 4S, I'm all Apple now and couldn't be happier! Not near the problems connecting to a wifi network with the iPad Mini, it just WORKS!
I have one thing to say as far as why you need both. It's two things you need for it to work though.
ios does not allow you to save to sd card, but android does. But you can save from ios to android and then save to sd card.
Or you can buy those wifi drives like kingston, airflash, or seagate stuff.
I'd say if you like apps more then ios is better.
If you like on the go usb more than android is better.