Just bought a Patagonia Black Hole Mini MOC 26L for cabin use. Neat design, largest bag you won’t pay for on budget airlines (fits under a seat), straps for rucksack mode. For my jet-setting oldest son for travel. Will manage a weekend away with a laptop no trouble. He’s studying in Dublin for four years, so needs those cheap flights and can do without price gouging check in fees.
Me? I travel light with a Barbour waxed cotton weekend bag. That’s sees me ok for a week. For more serious travel, I have a victorinox pull-along expanding case that’s survived many years of abuse. One down from Tumi.
My general advice is buy smaller and buy quality. Your kit/mess expands to fit the bag you’re taking, so take a smaller bag and use judgement. We have some cheaper Delsey and Antler huge cases and they are of modest quality but large volume.