Re: OP. I operate in both modes. Spirit Airlines is the extreme on traveling light; I went to Costa Rica for 3 days and Cancun for 5 with only a rucksack (their maximum to take free). On Delta I'll still do the checked bag (a Samsonite hard-shell) IF I have a rental car for the duration. If not, I have to tailor the packing to the situation (e.g. a backpack).

Flying as an air courier in the early 90s (when it made some sense and you could earn miles doing it) was an education in traveling light, as I was limited to the carry-on allowance only, even for 2 weeks in Asia.