We used the cares system on our recent 4 hour flight and it worked great! Connor is still under 2 years old, so he is not required to have his own seat, but was very proud that he had his own just like mommy and daddy.
The cares safety device was incredibly easy to install. I slid it over the back of Connor's seat, (in between the seat and tray table behind) and adjusted it to be in line with Connor's shoulders. The seat belt fits through the cares three point harness and when in place, looks similar to the harness on a car seat. (*But it's for use on airplanes only.)
During the flight Connor was content to sit and read his books, play with his toys, eat his snack and watch his own "tv" in the seat back in front of him. He also had a nap. He was thrilled not to be held and didn't ask to get down as often as he does when he's sharing a seat.
It's a terrific system and fits very easily into my purse. It keeps Connor safe and gives him a sense of freedom. The cares system is now on our essential must-have-for-travel list.