I totally love the AI 13s and compared to the 12s, they are definitely better. In fact, they are my main indoor gym balling shoes over my Hyperdunks (retired), Kobe III (wear once in a while), Durant KD1 (wear to mix things up), and my Lebron VI.
Fit and comfort: They are stiff and don't breathe very well since the uppers and sides are one piece without vents. Even though they are stiff, they really conform to your feet if you get a pair thats true to your size since it reallys wraps around your feet like the Kobe IIIs. My main complaint of this shoe is that the top layer of the insole is smooth and does not have an arch to keep your foot in place so you better have the shoe fitted cause if you get it even half size too big, your feet are going to slide about during balling. The cushioning is somewhere between Nike zoom and Adidas adiprene. Its not as soft and responsive as zoom but nowhere near as hard as adiprene.
Performance: The Hex ride system is functional but nothing really extraordinary, it does its job and the herringbone pattern for grip is good-to-really good. I don't get the squeaks as often as my Hyperdunk, Lebron III, or KD1, but is quite dependable.
As an overview, I really like them cause they fit well, I love how it looks and performs, and the best thing is that I haven't seen anybody wear them since I got them! I see everybody in Hyperizes now and they are absolutely the worse shoe I have EVER gotten and worn. Just to warn you though, since the shoe isn't well vented, your feet will sweat and get hot. I still would recommend them as long as you don't play in the same gym as me =P