This is one of those topics where people are very split, I think it totally comes down to personal preferance and style of music. If you're playing something totally chill and jazzy, you're probably not going to want major attack, so most wouldnt use a pick. Then again, some of musics best bass players used a picked exclusively. Paul McCartney, Jack Bruce, Noel Redding, even more modren bassists like Mike Dirnt. If you know what you're doing, you can produce a nice fat tone with a pick, its all in how you use your tone controls. Personally, I use a pick almost exclusively. Many say that's common of guitarists who go to bass second, but I just find that using a pick gives me far better control, speed and percision. Youl can check out some recordings Ive done. I like to think of myself as following in the path of bassists like Noel Redding, in the sense that It's his tone I love the most.
http://www.myspace.com/neotokyotheband
Ultimately though, if you really wanna get down and dirty with your bass, learn both styles. If for no other reason than to impress your friends
