We could have used one of those seats the 1st time my DS (at 3 ) flew. He wanted to keep opening and closing the tray and window shade. The poor woman in front him had to be annoyed. On the other hand, I think the bulkhead seat would have given him more freedom, and he would have wanted to get out of his seat. Maybe, the airlines should have a "kids only" section where they can play,scream, cry, kick and dismantle the plane without bothering anyone. lol!
We almost always fly Air Tran to Florida and they now have a on-line check-in where you can make your own seat assignment 24hr ahead. It works great.
Also, we always wait till most everyone has boarded, no need to sit longer than we have to. But only do that if you know your stuff will fit under the seats because the overhead storage may fill up.