I don't consider metallica metal really..
To be pedantic, Metallica are most probably classed, or were classed as, 'thrash metal' which by definition is a sub-genre of the greater beast that is 'heavy metal'.... so technically they play a variant of metal.
Admittedly shit metal at the moment.
I agree with you on the point about James Hetfield... considering he's supposed to be this "almighty" "legendary" etc, vocalist, he sounds like nothing at all interesting / special to me.,
I mean there's vocalists out there that don't on their own sound interesting or special, but then when you put their vocal style to the type of music their band plays, it works as it's virtually a contrasting style to the crunch of the riffs... ie Warrel Dane and Nevermore.