How Rude! Makes you wonder how they're using it in the car too.
I do think that a regular car seat is probably more comfortable on the plane than the CARES, for smaller kids. The Cosco Touriva is one that was mentioned here on the Dis when ds was younger and that is what we bought for travel and used it as a backup seat in MIL's car too, until he outgrew it by height (it's a pretty small seat). It was great for travel though - fairly light and easy to carry. Cosco has since redesigned it and it is now called the Scenera. It can be found at
Walmart/Target/Kmart for $40. They even have a pretty pink one for girls now.