Samsung Galaxy Tab 3 10.1 vs iPad 3rd Gen?

I'm a college student looking to purchase a tablet because the cost of my textbooks for this semester is ridiculous. I'm studying health science and physical therapy and will be using the tablet for mostly non-science books. I think I have narrowed it down to the Samsung Galaxy Tab 3 10.1 and a refurbished 3rd generation iPad. As I said earlier, the most important thing for the tablet is to support textbooks. I will also use the tablet for browsing the internet. I'm familiar with both operating systems. Are there any differences in the textbook aspect of each tablet and what are the differences between each tablet?

Another thing that I'm concerned about is at some point a few years from now, whether Apple will stop supporting updates for older iPads. I bought an itouch in 2010 and Apple has since stopped supporting updates for it. My ipod can no longer download new apps and is extremely glitchy. I would hate to spend money on an iPad and only be able to use it for a few years.

Also, what are people's opinions on the Lenovo A10 tablet and the Lenovo Idea Pad 9.7? I don't love that these don't have a physical home button, but if someone spoke highly of it, I would considering purchasing one of these.

I would rather recommend to get an iPad 4. The Tab 3 is not so good but the iPad 3 is older so it will only get (hopefully) up to iOS 9. And iOS 8 is confirmed for iPad 3 too, but the iPad 4 will be faster and smoother and better.