I really learned to manage a flatpick when I started playing tambura (the Serbian/Croatian one) because the style required a lot of tremolo--played fast, clean and in strick tempo--(oh, and really loud, too)--It was hard to learn at first, mostly because I had to undo a lot of bad habits, the worst of which was a careless disregard for how I positioned my hand, the pick, and the instrument.

The real problem that most folks have with their flat picking is simply that they never concentrate on learning or practicing good pick technique. A lot of it has to do with the fact that many contemporary guitar players are self-taught, and tend to fudge stuff they didn't know how to do, if they even hear it in the first place. Also, in blues, rock, and folk music, the guitarist generally doesn't carry the melody--Another thing is that, with amplification, the guitarist doesn't need to worry much about getting volume out of the instrument--

Whatever the reason, if you listen to a lot contemporary players, and compare them to the old guys that they are emulating, there is a lot missing. My general feeling is that the kind of pick you use is kind of a red herring--they way you use it is what makes the difference.

When I was playing the tambura(and, to be honest, I was strictly a bargain-basement tamburasi), I tried every different kind of pick, so I generally had all shapes and sizes, from triangular and felt things to stone picks..I was particularly fond of picks that had cork of various shapes and sizes attached. One day, I was working up some Russian music with a friend who was a great balalaika and domra player. She asked, "Do you have an extra pick?" "Sure, what kind do you want?", "It doesn't matter, I can use anything." And she could.