I've used metal fingerpicks all my playing life, first on the Tama I had until 1984 (yes. I know. But it sounded great), and then on the Taylor jumbo I've had ever since (ditto). The only difference I can tell is whether I'm playing cleanly or not. If I am, you shouldn't notice the picks. However, cheaper ones tend to be made of thinner metal, and that is an issue if only because they are more vulnerable to shape changes -- I want the picks to stay exactly the same size and shape I've tortured them into.

That said, as part of this revival I've switched to a nylon pick on the banjo, because it *does* seem to me to have a warmer sound, and unfortunately I'm not playing cleanly enough (yet) to avoid metal clashing. Also makes it easier to identify the banjo fingerpick, of course. :)

wg