I am drawn between reading from real university textbooks, laser printed version or pdf version. I get glare reading from the former two. The situation is worse when reading those thick pillow-like Physics and Engineering texbooks. In the case of buying an iPad PRO 12.9" mainly for reading, should I get a glass protector or a matte one? I guess glass protector allows crystal clear reading but a matte one may better due to less reflection from my desk lamp. Any comment? What app is good for reading/annotating pdf version of university textbooks? Can I also change the background of the page such as the yellowish one?