I've flown kilted once. I removed the kilt pin since I expected there could be a problem with that. That went in my checked luggage. One young TSA agent in San Diego asked if I could take off the buckles. I told him he really didn't want me to try. So it was the lunge procedure described earlier. Takes an extra 5 minutes or so as long as your carry on checks out ok.

It was quite comfortable.

None of my seat mates said anything, but one guy caught up to me in Atlanta to inform me that you don't see many kilted people in Atlanta. I told him I found that odd, since it seemed like the perfect weather for a kilt.

I was wearing a SWK Black Watch kilt. It was warm enough (and I too often tend to feel the cold easily). All-in-all, a pleasant experience.