I prefer the sound I get with a pick.
With the Peavey Mark VIII Bass Amplifier I use, I can use the shelving controls along with it's 9-band EQ to get a perfect fat sound that is also crisp and clean without having to beat the crap out of it.
If you've ever been to see
my band's myspace page and either heard the songs or watched the videos, you know that the sound quality is less than perfect. They were quick, shoddy recordings that didn't pick up the duality of my bass sound properly. With the combination of the Amphead I'm using, the Ibanez GSR205 bass I use, the specific material and thickness of Clayton picks, and the D'addario strings I use, I get a very rich, full sound that is crisp with a very clear attack.
Since my band plays metal with only one guitarist, it's crucial that my sound be cutting, fat, and loud, but also CLEAR, as I'm left hanging in the breeze quite often by the guitarist, and if the bass isn't EQed just right the overall sound is totally lacking.
If I was playing blues or funk, you're right, I should be using my hand... but I play metal, and with a raised bridge and round-wound strings (like I use), playing with one's fingers would just sound like poo.

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