Agree with pp. we use CARES and it's so much easier than taking a car seat.

On the flip side, just flew with my 2 year old and a CARES harness and it was great. She was able to move around more, she doesn't sleep well in her car seat, etc.

I think a lot of this depends on your individual kid.

As an adult being strapped in to one position and not able to move much for 10 hours would be torture. I would never do that to my child.

A short flight - sure, but 10 hours. Nope.

We had the same experience on a flight to Europe this summer. My son likes his car seat and obviously knows in the car that he has no choice but to be in it. That transferred to the plane because other than one walk up and down the aisles he was strapped in and sitting comfortably the whole time. We had a lot of trying to kick the seat in front of him but with distraction it wasn't such a problem.

We just got back from a trip with our 2.5 yo, and SO glad we brought the car seat on the plane. With 2 adults and one kid it was not at all a pain to lug around (I would think twice if not with someone else for an extra hand). For bringing it through the airport, we used the back tether strap to hook over the luggage handle so we could wheel it along, no extra gadgets needed. Once we checked the luggage we just needed to carry the seat to the gate, which is annoying but not awful.

Installing was easy (much easier for the return trip when I already have some practice). DS was comfortable and wasn't able to move around too much, and even got some sleep. 10 hours of flying total, and I think we had about 4 minutes of tears. No kicking the seat in front of him, though we repeated the rule many times. Much better than expected. No regrets and I would do it the same way next time.

Different for each kid, and each flight, but it worked this time for us.