Looking for some recommendations. I mainly fly domestically (US) and primarily on Southwest (thank you, business traveler wife and my Companion Pass!). Following the "packing light" mantra as much as possible, I rarely check a bag, preferring a 21 inch or smaller wheeled bag and a small to medium sized backpack for underseat storage. It's been a good system over the years.
I recently purchased a Samsonite large wheeled underseater, and am pretty impressed. The bag holds a ton for its size, and by packing strategically, I can fit 3-4 days of clothes in it, along with toiletries, with room for my iPad and (small) bag of chargers, cables, etc.
Before I ordered this bag, I did a little research on underseat allowances for domestic carriers. (I excluded international and US commuter airlines due to the more restrictive guidelines for carryons in general.) Needless to say, there were a LOT of variances in HxWxL depending on the airline, aircraft, and seat location.
When I took the Samsonite on its "maiden voyage", I found that true to what I'd read, the bag fit under a middle seat of a Southwest 737 fairly easily, but not the aisle seat. And as it was a two-hour flight, the degradation of legroom wasn't that big of a deal, comfort-wise.
Here's the question: For those of you who use these bags, are there any you've used across different airlines with general success? I realize that there's no "one size fits all" solution here, but just curious as to whether there are any rolling underseaters that pass muster between, say, American and United, for example.
In any case, this Samsonite is a gem, even if it's too big for some seats. It's small enough to easily fit in the overhead while sporting a lot of packing space.