Other than the bigger seats, you also get better food and free booze, plus pre boarding, but no way is this all worth an extra $500, unless you have $$$ to spare. (I spent years flying coach, and it wasn't that bad, but then I got to the point that either I was upgraded or could just pay for F, and now that I'm used to F, I wouldn't want to go back to coach. But you might be doing your son a favor by encouraging him to fly in coach for the time being.)