Faster fire rate due to faster reload time on the bow, makes it a little easier to use if you were close proximity with a roaming horde. Xbow you will have the issues with reloading and probably take on a few hits and get surrounded vs that same horde. Xbow good for sniping yes, good for 1st shot on sleepers + stealth bonuses, having said that I reckon the bow can 1 shot any sleeper with steel just like the xbow. Bow could be viable for a horde night (if specced deep into agility)+ headshots with iron arrows at least, xbow would be too slow I bet.