I tend to think Harry isn't more messed up because somewhere inside him is the memory of being loved by his parents. His first 15 months of life seem to be the biggest difference between him and Riddle. Riddle never had that love at any time in his life. Harry had it and even if he doesn't consciously remember it, I think it is still there in him.

The decision to leave him with the Dursleys was made within 24hrs of his parent's murder. Part of me thinks the decision was too hasty and if they'd sat down and thought it through they might have come to a different decision. Also, the idea that a *letter* was enough to make a deal with the Dursleys strikes me as naive to the point of ignorance. Perhaps Harry was safe from the outside world there, but he was most definitely *not* safe from his "family".