I used my retina mini in classes last semester and found that it was doable. I've been able to look at PDF's and slides just fine, then again I don't mind pinching in a bit if something is a little too small. Note taking took a little getting used to at first on a smaller screen, but there's always the option of an external keyboard. I tend to use the devices together when studying, sometimes by having powerpoint slides on one device, and notes on the Mac, so I don't have to switch between spaces on the Mac as much. I do like that the mini takes up less space on a desk when I'm in class. I liked the size of the mini in my hand when I was walking around with it, but I wouldn't worry about weight with either of them, since they're both very light. I think either device will do what you want just fine, I just preferred to carry around a mini.