First Glance: Looks interesting, perfect Swashbuckler PRC

Canny Defense (Ex): When not wearing armor or using a shield, a duelist adds upto 2 points of Intelligence bonus (if any) per duelist class level to her Dexterity bonus to modify Armor Class while wielding a melee weapon (to a maximum bonus equal to her Intelligence modifier). If a duelist is caught flat-footed or otherwise denied her Dexterity bonus, she also loses this bonus.

I'll examine it in more detail later.