This is not a city commuting bag. We tried wearing the Flow to work in New York City using the subways and found ourselves nearly bowling over fellow travelers. Wearing the Flow feels like wearing a small suitcase on your back. It does handle its weight well, but it has a feel that's less like a standard backpack and more like armor. The Flow's bulbous size makes it prone to tipping over when placed on the floor, but its excellent thick handle on top is great for carrying short distances.
We'd recommend the Flow, instead, as a fantastic airline carry-on backpack, or a general gearbag for weekend car trips. Roomy and sturdy side pockets, lined with slightly elastic neoprene, are useful for everything from water bottles to bundled power cords (just don't put them in the same pocket). We never lacked for pockets on the Flow. And, again, we appreciated that all of these compartments never interfered with the laptop sleeve tucked away--nearly hidden, in fact--against the back. It's definitely one of the most useful and well-designed large bags we've seen, but we don't have an urge to use it every day, like we did with the Squeeze. It will remain with your luggage, not your jacket and keys.
The Booq Boa Flow comes with a limited five-year warranty covering defects from "normal use," and won't apply for damage that Booq deems was caused by physical abuse or negligence. The bag will be replaced, or if the Flow isn't available, be substituted with a percentage value of store credit based on lifetime ownership of the bag.