Attack speed bonus thief acrobat enhancement "thief acrobatics" is not functioning. Or at least it doesn't show up on the character sheet.
It also doesn't say what type of bonus it is, leaving it ambiguous whether it is intended to stack with haste or not (the live equivalent does stack with haste). This is the kind of in-game documentation this game desperately needs. Bonus type matters a great deal, so it should say on the tool-tip what kind of bonus it is.