Depending on how much you want to spend, I’ve found GoRuck’s products to be absolutely bomb proof in the past, and their GR2 should meet your size requirements https://www.goruck.com/collections/gr2.

There are a could quirks to them though – they unzip completely open, but are a single storage compartment design. I mention it because it’s a design I absolutely love but if you are looking for a lot of interior compartmentalization maybe look elsewhere.

The biggest potential downside (side from cost) is the tacticool styling and the weight (although that weight is due to the durable fabrics). I should also note that I have bought from them several times (for myself, and then for family), but not since COVID and the consequent effects on many businesses profitability. As of when I last bought they were still well-made and we’ve beaten the heck out of them with no damages.

Peak design travel backpack. Can hold 45 liters, but you can snap it down for a smaller profile. I did a ton of research and this one came out on top and I can’t be happier

I can’t speak for 5.11 quality today, but I got my Rush 12 in 2010 and it’s still going strong. There were a few years there where I abused the hell out of it, too.

I’m a shoulder bag office lackey now, but the 5.11 remains my weekend bag. Other than the regrettable tacticool style, I have no complaints. The Covrt would probably be decent.

You may also also want to ask about this in !onebag@wayfarershaven.eu - we love talking about bags.

Someone on Reddit created this website(I think) and it goes over a lot of different things https://theperfectpack.com/