I go 120 crossbow / 130 2h with a regular crossbow, for reload speed and because I am a 2h crutcher in melee. Its fairly accurate, more than it should be. I definitely advise 15 str regardless of crossbow, just for strat usage. (people tend to just by arbs when they have the money to do so).
I know, Karma already posted and knows way more than me, but hey, more advice doesn't hurt.