Malcom Gladwel had a book entitled David and Goliath. He doesnt question the actual account, but suggests there are good reasons to believe Goliath wasnt all that. That he too has the same pituitary gland disorder which can also cause diplopia (double vision), which would explain why Goliath says "so you come to me with sticks" (plural), when david only has his staff. Also, he had a shield bearer, which would possibly indicate some other restrictions related to that disorder. I cant think of the name.
His point is more about how seeming advantages can be disadvantages, and vice versa, using this story as a set off point with things not being as lopsided as they may have seemed. It was pretty interesting.