Assuming you're completely specced for attack speed and doubleshot with the respective weapon, which weapon is faster? And would another weapon be able to attack faster? I'm talking just hits/minute here, with no regard for actual DPS.
Edit: also assume at least 3 monk levels in the case of shuriken for ninja spy 2
Edit 2: I'm talking about repeaters too,not just regular xbows (unless they can get faster than repeaters somehow)