My son started middle school this year and carries around a ton of books. The backpack that we bought for him in September, Grip by High Sierra, is completely falling apart. We're looking for something new that is big enough to carry several binders and textbooks (even though my son is a pretty small kid) and that is sturdy enough to last for a while. I was looking at a Kelty Redtail, a Kelty Peregrine, or possible a Burton (although all of the Burtons seem to be a lot smaller). Anyone have any recommendations for a big, sturdy backpack? Thanks!