I'm 5ft 3in so can't pinpoint taller people but this one fits quite nicely under the airplane seat in front of me on an overseas flight. It was a great purchase. It has all sorts of pockets for organization and storage and fits my 15 inch laptop. I wouldn't say it was as secure as a laptop bag, but the velcro held it in place. You can easily fold the laptop in half in this area and place it in the sleeve, and there is padding where the laptop fits. The attached battery compartment is really handy for long trips without access to a power outlet. Not only was the wide open mouth good for me to dig around to find things I had set in, but when the TSA singled them out for review, they made that review quicker and easier. It's also quite stiff so it stood open well while I was digging around rather than having to move materials around like with flexbags. It didn't have room for my laptop's fan, so I had to pack it separately. I have an opinion on water resistance as I haven't had to test this feature yet. We travel a lot and so far it's been solid and I love it.