Very cool picks. They are perfect for playing metal (solo and expecialy rythm parts). They make very bright sound and you can achieve very fast attack because it is sharp. But for playing clean sound they seem to me to "naked" (not enough obertones). It's better to use not sharp picks.
This picks are the same as Dunlop Ultex Sharp, so you can buy them insted. Maybe Hetfield's picks are a bit better about grip because of prints. But I don't feel it while playing.
Ultex picks have better durabillity (versus Tortex series), but they play not much longer (1 week - Tortex, 10 days - Ultex). But for me it is not so significant. Sound matters more!