I go carry-on only but it's mainly because I find the stress of parting with my belongings not worth the hassle, and I find the time savings valuable. (And I respect that plenty of people find the stress of hauling around all their belongings not worth the hassle, and they check it. There's no right or wrong here.)

Keeping my stuff with me gives me peace of mind. In 2003 my friend and I got to the baggage carousel in Phoenix just in time to catch a thief walking off with my bag, but, unfortunately, after a thief had walked off with hers.

Keeping my stuff with me has occasionally saved me hours, such as when I was barely able to catch an earlier connecting flight to my destination rather than wait for my very delayed connecting flight. Agreed, this is an outlier and probably shouldn't influence one's "calculations."

The one item I've checked since 2005 was an Ethiopian dining table that I bought in Addis Ababa, and I found the whole experience of checking it extremely stressful. However, the stress was partly because I was on a connecting ticket after an airline-provided long layover at the Hilton, and they brought us back to the airport only about an hour before the flight. I'd have avoided some of the anxiety by going earlier on my own.

Last week I escorted a friend to EWR and watched her print her luggage tag, loop it around the handle, and wait in a very long line to send the bag off. She's pretty savvy with such things but I'm not sure I'd trust myself to affix it in a way that wouldn't have the airline's lawyers saying, "Well, your bag didn't arrive because you didn't attach the tag by sticking flap A onto flap B with the 2.3 aerometers of space as mandated in exhibit C."

In February I visited eastern Russia and Indonesia. Packing for a 130-degree temperature spread was not a problem with just a carry-on and a Scottevest jacket with lots of pockets.

To get back to the original question, then, the packing plan's predominantly personal preference plus perceived potential problems, perhaps.

Seth