Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Sturdy build quality

I purchased this backpack due to its CORE protection system. As commented in a previous review, it is a rather wide backpack. Much less flex in the outer shell than a 'normal' backpack. Although I like the built-in CORE protection, I'm may get a Brenthaven expandable Trek backpack for everyday use. It does not have the CORE system, but does have more pockets and a more standard backpack form factor. I'm thinking this backpack will serve me well for travel.