CARES v Car seat on Airplane for motion sickness

[WaturMama]

We are flying across the USA with our 34 lb, 4 year old DS who has vomited the last two times he was on long plane rides. Those rides were 10 months ago, however. He was in his car seat those times. I'm considering using CARES this time: (http://www.kidsflysafe.com/)

Any words of wisdom on which would be better?

As I see it:

pluses of car seat are, he will be higher and can look out the window, he's used to it and maybe more likely to sleep, not an extra expense...and less important, we have to bring it anyway and this way won't have to figure out how to check.

pluses of CARE: he will be father from the seat in front of him, maybe more space=good, novelty=good, if he does vomit it won't be on the car seat...and less important, easier to install, don't have to carry car seat through airport.

[ChetMC]

No Difference

I don't see it making a difference for motion sickness. A better view out the window is unlikely to help. In a car, looking out the window helps to clarify the mixed messages your brain is getting about the motion. This isn't the case in a large aircraft at cruising altitude. There are no reference points out the window.

A carseat is definitely easier to sleep in. A carseat is definitely safer in the cabin than checked or even gate checked.

Would you consider giving Gravol/Dramamine for the motion sickness? It's available as a liquid for kids over two. DH has his private pilot's license, and we've given it to our oldest when she goes up with him. We don't have problems on commercial flights, but I think small aircraft are worse for motion sickness.