The budget airlines are more strict with carry-on dimensions and weight. The mainline (bigger, established) airlines generally are more lenient, but if you’re on a small plane—smaller than a 737, such as on a regional jet—then the size limits must be enforced because there’s no way the pack you mention will fit in those tiny bins. To me, it looks like it probably would fit in a 737 (which Ryanair fly), A319/320/321 (which Easyjet fly), and any plane across the ocean. Some airlines only allow 8kg for carry-on, and that’s only 17.6 lbs. You’d either have to check the bigger bag, or pay excess baggage fee.