I don't think anyone can deny that Khan is probably the gutsiest fighter in boxing today. Biggest balls in boxing bar none.
The truth is Khan doesn't have the greatest chin, or the worst chin - he has a pretty average chin. He took shots from Maidana which others have succumb to, he got dropped by Garcia but so have a lot of other fighters including Morales.
The only reason Khan got beat by Garcia is because he got taken out of his gameplan by Angel Garcia - he tried to brawl, should have boxed. Even then, Danny could still catch him with a good shot but it's unlikely. If Khan sticks to boxing and aims to land more punches every round instead of KO his opponent I don't think Garcia has a great chance of beating him again. But, the way Khans talking he sounds like he wants to try to KO Garcia and that will be his own downfall, he'll get caught again.