In the new vs old argument, consider this ...
If you account for (and equalize) the equipment in each era, who would you take:
1. Rob Pannell or Paul Rabil with a 1956 wood stick
OR
2. Jim Brown with a Rabil X (or Super Power).
Sorry, on this analysis, the old guy wins in the old era, and in the new era. Our boys are not any more highly evolved than the athletes back in the day. Better trained with an earlier focus, yes. But your kid isn't ever going to be Jim Brown. And he probably isn't going to be Rob Pannell or Paul Rabil either.
And honestly, you would probably not have let him play the "old version of the game" if you could see it first hand -- you are underestimating the size and speed of the guys who played long ago, and you are discounting toughness to a point that, back then, would have been deemed dangerously foolish. Anyway, have a read:
http://sportsillustrated.ca/vault/article/magazine/MAG1129606/index.htm
