Honestly I am too, although I tend to remember the name of the vocalists of most bands...I couldn't tell you who plays the instruments though. I guess that would be because you don't get too many solo guitarists or drummers etc. these days. I think it's more classical music that has instrument-focused albums.
It seems like a lot of metal/rock groups treat covering a Metallica song like a rite of passage or something, haha.
Agreed, Disturbed are fantastic - both their covers and their own songs. One I actually really like is Xandria's version of Don't Say A Word, which is from the perspective of the woman in the relationship, so it's more like a really clever companion rather than a word-for-word cover. Honestly a lot of pop songs are actually pretty disturbing - I grew up listening to Diana Ross' Chain Reaction, because it was my mother's favourite song at the time. When I listen to it now I have to wonder how on earth she got away with having those lyrics!