As a travel writer at Wirecutter, I’ve talked to many frequent fliers, including flight attendants, The New York Times’s Frugal Traveler columnist Elaine Glusac, and even Conan O’Brien, host of comedy travel shows that have taken him to some 20 countries.One thing most of them have in common: It’s carry-on or bust.Their reasons include efficiency once they arrive, never losing luggage, and the pure joy of packing light. “You’ll be so much happier with yourself if you bring less and make sure that everything works together,” Glusac told me.So when I talked with Wirecutter’s intrepid travel experts, who test and recommend both checked and carry-on luggage, I expected more of the same.Not so. Our travel experts love to check bags. They might go as far as to say that the hype for carrying on is kind of overrated. Here are their reasons (and some advice for when to carry on instead).