My DD is a 5th grade teacher and they use computers a lot now. They have gone to i-pads now over all the other items. My other DD bought the I-pad mini because she needs the internet in what she does and buys a lot of e-books. They really like that they don't need to buy extra protection like with the others.
Sorry I can't comment on the others because everyone I know that has bought the i-pads over the other items.