i play bass myself and i personally enjoy the freedom of playing with fingers, rather than the percussive sound of the pick. however, i'm not going to preach about how fingers are better and how it gives you a better feel for the instrunment, like many bass players in other forums do. i guess it's all about personal preference. if you can rock with a pick, then do so.
also, i think some songs are better fitted for picks than fingers.