Right now Cat is "best for stealth" just bcs its small (so you have much lesser chance to hit the sight cone) and have huge Dexterity score compared to other forms ...
Just two days back i was sneaking as cat (love the new model, btw) in "Dragon's Lair" (the place where Tiefling Thieves are hiding) and i was spotted ... instead of decerasing reputation and grumpy comentary, Tiefling kids just yelled "here kitty, kitty, kitty" at me, and then they walked away, one of them even wanted to keep me as a pet.
So ... there certainly IS some non-combat reactions from some npcs (non hostile npcs as it seems) ...
And those Bandits as are sadistic bastards who dont like kittens ... since now im gonna kill them on sight, no talking anymore!