I'm sorta down to these two bags: Patagonia Transport Shoulder Bag 26L: http://www.patagonia.com/us/product/transport-shoulder-bag-26-liter?p=49440-0 Tom Bihn Pilot Bag: http://www.tombihn.com/travel_bags/pilot.html I picked these two for size, looks, and features. My needs: 1. fit under the seat in front of me for most US domestic travel, even in Coach. 2. Be able to slip on to my roller bag handle (both bags above do) What I usually pack in this sort of bag: - 15" Inch Macbook Pro Retina (thin, but yes a bit wider than a 13" laptop) Laptop - laptop charger, phone/tablet charger - Couple magazines or book - Boarding pass, etc. - Nexus 7 tablet (similar to ipad Mini size) - Bose QuietComfort Headphones (this is important because these always are tough to fit because of how deep the case is) - Random items that may have not fit in my larger roll aboard or, if needed, checked bag - Water bottle and/or snack I point out the Bose headphones because when I use my current personal item (a Thule bookbag), they don't fit great, and the book bag is tough to get (items end up going to the bottom of the bookbag, very hard to get!) Current dilemma: The Tom Bihn bag seems more geared towards the kinds of items I am packing, while I like the Patagonia clam shell and book style openings of two of its packs. One of my biggest current issues is I use a bookbag for under the seat storage. Not only is it a little too big to fit sideways, but it's impossible to get anything out of it in the main compartment because it's narrow and obviously only the top part of the bag opens up. So it becomes a bit of a disorganized mess. It's also just not made as specifically for the kind of items I'm packing, other than a laptop sleeve and an easy access pocket on top for keys/phone/passport. My worry with the Tom Bihn is that because its main compartment doesn't open clam shell or book style I might feel the same way. Then again, with other multiple compartments that are more useful than my bookbags, and a much "shorter" bag, these same issues seem less prevalent in the Tom Bihn. I also can't tell if that Patagonia bag would be too big for under the seat storage. I did see a review on eBags that said it would fit. I'm also interested in other bags if folks have any recommendations!