I am thinking of returning my Keepall 55 and getting the Sirius 55. While I love the Keepall, I have a fantastic leather duffle that I love and get compliments on all the time. My question is -- can the Sirius 55 be used as a carry-on? According to the dimensions, it can be used as a carry-on for most airlines but I was hoping to talk with folks with first hand experience. Danke!