It is still a requirement that your carry on will go under the seat in front of you. I’ve always made sure our two carry ons meet the airline of choice’s luggage requirements even though it leads to arguments with my husband. He’s way to casual about the whole thing than I’m willing to be. I do not want to run the risk of having a bag refused so I’ve measured them ad nauseam. For years I’ve used a hard sided carry on and hubby uses a wheeled backpack. For the upcoming trip, I’m switching to a soft Lug backpack. Like Dax mentioned, some of the stuff people walk on board with makes my head spin and, yeah, ticks me off. I fret the hell out of my bag weights and size and people wander on with way over sized bags and multiple bags :-X I have been on flights where the overhead bins were full and attendants were looking for places to put bags. Personally, I think bags (legal size & weight) should go in the bins first and, if room after everyone has placed their bags, then coats, hats, etc. can go into the bins. It’s easier to shove a jacket under the seat than a bag! We fly Club Class and you would think you wouldn’t have issues with overhead bin space due to only 12 passengers in this section. We were on 1 flight and the bins over the first two rows, one side of the plane, were taken up by Air Transat stuff. We were in one of those rows so, after that, I made sure not to select those seats on future flights.