Flying witha three year old

I will be picking up my 22 in Nov. and my son is just turning 3. (30 lbs). I thought a booster seat would be a bit easier in the plane than the conventional carseat I use in the car. Has anyone with a similar age child put a booster in the back and how does it work? Any difficulty with the 4 point harness? Do you use the boosters that have their own belts or the kind that have no belts and rely only on the belts in the plane? Any advice would be helpful.

I also have a 3-year old 30 pounder and a -22. He loves to fly, but usually falls asleep or passes out from the altitude, not sure which ;-). I have found that he is usually more comfortable with the old fashioned carseat because it positions him in a more reclined position for sleeping. In the booster seat, he is more upright and he usually falls asleep with his chin on his chest.
For securing the seat in the plane, it is easy to flip the seat facing down so that the base is facing the back of the seat and thread the belts through the base. Rotate to the upright position and then tighten the belts. You will want the buckle to be offset towards the center of the plane for access when you remove the seat. It can be a real bear to get unbuckled if the buckle is under the center of the seat.
I have also had my son in the front seat before. His legs are not quite long enough to interfere with the stick if I slide the seat all the way back. The door handle is very difficult for him to access as well.