UNDERSEAT PRO Airline Personal Item Compliant Backpack Fits Frontier Airlines, American, Allegiant & More (18x14x8 in)

I've been trying several underseat bags and packs and this is probably my favorite. The rectangle shape maximizes the capacity, and compared to a wheeled bag this has noticeably more room inside. The canvas-like fabric gives the bag some structure which helps to not overpack the bag. As soon as I received the backpack, I practice packed 3-5 days of clothes, including shoes for a business trip, plus toiletries and my pouch for cables, earplugs, etc. This bag even has a pocket in the back of the main packing section, where I put my laptop. You'll want to use a sleeve because the pocket is not padded. This is an advantage to me, as I find backpacks with a padded separate laptop section often have reduced space because of the padding. With the Underseat Pro backpack, I get to decide how much padding I need through picking an appropriate sleeve. You could even just put a laptop (or tablet) inside and pack clothes around it, if you like to live on the edge. The backpack straps really help since you can pack this out quite heavy -- I wouldn't want to carry this by just the top handles. Compared to a wheeled underseat bag, there is noticeably more room in this. If you're flying Frontier with a personal item only, don't pack this out fully or you may have difficulty if you're asked to use the bag sizer; it's going to stick up a little above the top, and/or you may have to give it a push to get it to slide down into the sizer. For non-budget airline travel, the backpack with my Underseat Pro rolling bag will really maximize my packing space, while easing the anxiety about finding space in the overheads as the Underseat Pro are a nice, compact size and smaller than most airlines' maximum size for carry-ons. This Underseat Pro backpack is bound to become one of my favorite personal item bags, if not the favorite.