Well, should be obvious to some of you what my favorite band is......
On the subject of Metallica's transformation: I see it as just a form of re-invention. Master of Puppets was the definitive album of the thrash-metal era. To try to top that would have been futile. And the Black Album, from top to bottom, is one of the best rock albums ever. After that, they just had to go into a new direction and re-invent their sound. So James Hetfield gave Kirk Hammett a bit more freedom of expression.
Now, most of the songs on Load are pretty bland, I'll give you that. ReLoad is another story. Some pretty good songs there, particularly at the back end of the album. 'Low Man's Lyric' is uniquely haunting and somber, and 'Fixxxer' ....holy crap! Just try listening to that song with some good headphones.