I've been searching forever, but most reviewers comment on how a case feels when holding the iPad in your hand or around the house... I'm a student and plan on putting my iPad in a backpack most of the time with a few other books. I ordered a hard back shell for it and a screen protector-- will this be enough? I really want to avoid the cases with folding covers since I find them unwieldy and annoying, but I don't want to mega-scratch my iPad's screen or anything. Tips from fellow backpack stuffers?