I've heard one reviewer say this is smaller than expected, but hey what can you expect from a backpack that claims it is small?I bought this specifically because I was going overseas for a little over two weeks, and it survived like a champ. Fortunately, for me, no one tried to steal anything from me so the anti-theft features are still unproven. Yes there is no external water bottle holder, But then again wouldn't an external water bottle in an unsecured space just beg to be stolen? Especially, if it's one of those expensive insulated water bottles. Just put your water bottle inside. The inside is waterproof, I can tell you that because I accidentally crushed a yogurt container in my backpack, by just stuffing things in, and just cleaned the mess up with soap and water, and dried it with a towel. The zippers are as strong as the YKK zippers. It has one main pouch and two smaller pouches, one fits an 11" IPAD Pro perfectly, and the other which is rfid shielded, is for passports, etc... It carried about 20-25 lbs of stuff daily. including my insulated water bottle, medication, my battery charger, my ipad (which I never really used, not an Apple guy, but don't hold that against me).Oh another thing, the thin straps made it incredibly easy to go from a back pack to a front pack, for easy access to things.