I've loved my iPads--had one of each model since they came out--and use them frequently. I grabbed a mini on a whim, and while I use it sometimes it's just not as crisp as my iPad with the retina display. But the size of it is great.
I've been convalescing from surgery for the last few weeks and wanted to read whilst flat on my back. The mini was no easier to hold up than the iPad proper after a few minutes.
And I'm shocked to say this...but the cheap Lenovo 7" Android tablet feels nicer in my hand than the mini--though the screen isn't quite as sharp. But it was half the price of the mini.
I would say for someone new to tablets, if a mini reads well enough for you it's a good choice. But anyone used to a higher res screen would probably prefer the iPad retina. But there's a plethora of Android tablets out there, some of which are exceedingly good value. I use both iOS and Android extensively, and while I'm definitely an iOS dude, for many folks there's not much of a difference in terms of functionality and affordances between the tablet offerings for each.
But for long road trips, where I have to bring a work laptop, my iPad retina is my default device: light, easy and functional. Especially with the Logitech solar charged keyboard case.