Thanks! As for the experience, I can post it right now:

Scenario A - I had a vacant seat between us, and it was fine. We all felt very comfortable, and my son slept through most of the flight. So did we. I am telling you, I am so glad that we didn't pay the extra money for the full price ticket.

Scenario B - I can't feel my legs, and my head aches. It is DEFINITELY the last time I pull this stunt, and next time I am buying a seat for him. Now if you'll excuse me, I am going to waste a day of my once-a-year leisure trip and sleep it over.