I guess it's all up to one's preference! I play with my fingers and thumb. I have discovered that quite a number of very famous r&b/funk tunes were, in fact, played with a pick. In particular, "For The Love Of Money" by the O'Jays (bassist: Anthony Jackson). The old school cats here will know that one. Also, many of the old Shalimar, Dynasty and Whispers tracks were played with a pick by either Leon Sylvers or Foster Sylvers.