My number 1 low expectation character was Jak. I noticed he had really short combos, and the mass inverter launched really slowly with poor range. However, Jak is now my main and my most successful character, with many tools, cool supers, and decent matchups.
Cole was my biggest disappointment his lack of fluidity is just -.- aso n teh other hand jak can pull some really good combos off XD
I originally thought Sly Cooper was going to be trash because of his lack of a guard, but now he's quite frankly the most annoying character I've ever fought, even more so than Kratos. Kratos is annoying is crap, but he's easy to deal with because he's so straightforward, but Sly has a bunch of stupidly safe moves that make punishing him difficult, his invisibilty is TOO effective in FFA matches, then he has a counter on top of all of that, and even his level 1 Super is safe. Most people's level 1 supers are easy to interrupt, but he becomes invulnerable, like with a level 2, and the big hippo guy appears behind him only making the move even safer because it makes it hard to get him from behind with close range characters.
I also thought Nariko was gonna be a monster of a fighter, and although she is, compared to the broken characters in the game, she's nothing special.
Also, Cole is quite the decent character in my eyes. I have my issues with him, but he's still one of my favorite characters to use.