I'm always searching for the "perfect" travel bag. Not too big, not too small, just right. Something with enough space for what I need to take and not enough for what I want to take.
I've been a roller bag person for a long time, but I recently bought a backpack to try out. Because it was on sale for less than half the normal list price, and because it was my target size, I got this Eagle Creek Afar backpack. It measures 20.5x12.5x8.5. It weighs 1.7 pounds and the cubic inches are 2050. I like the strap arrangement. I tried it on with weight in it and it feels good, but the proof is always in the using.
I'll be using it for a domestic trip this fall, so I'll soon find out whether or not it was a waste of money. I hope it will force me to pack less. I'll use it in combination with a medium sized crossbody personal item like I normally carry.
I've had the RS Convertible Carry-on since 2009. My husband still uses his, but I switched to a roller bag when it became too heavy and bulky for me to put on, much less wear. I'm tall and wide, but I think it's the width that's the issue. It's 21x14x9, weighs 2.7 pounds and is 2500 cubic inches unless you expand it, making it 3000 cubic inches. Of course, expanding it makes it too big to be a carry-on.
I considered the RS Alpenzell already mentioned, but I think it is really too small for me at 18x13x6.5 and 1400 cubic inches, although the 1.35 pounds sounds good.
Everybody has their favorites. I hope you can find yours.