I bought my iPad for my senior studies and it was Great! I had been taking my MacBook to school but got sick of it. Better than a Laptop for battery life, better for textbooks, lighter, great for in class research for tasks, annotating books and textbooks. Did most of my writing in books as doing it all on a computer isn't the greatest idea. It was very good and that was under iOS 5 and 6 - many advances have been made since then.
I also had the self control to ensure I didn't waste my time on it. Surely with the iOS 9.3 education update, keeping a class on track would be much easier.
I think the problem is that plenty of schools will introduce technology for the heck of it. Money is dumped on iPads but no thought is put into making them work in schools, not to mention that technology is not even needed in many of the situations that it is shoehorned into. Teachers need to be trained and good workflows and integration need to be identified and taught.