There has been some mixed emotions about Lou Reed and Metallica's collaboration.I myself thinks it is genius what Metallica and Lou Reed are doing.  I would like to see more collaborations with artists that don't usually don't go together. You take the example of Headcat which features Lemmy of Motorhead and Slim Jim Phantom from The Stray Cats. This collaborations rarely happen and i honestly think its because of the fans that are not use to hearing the bands normal sound.

You can check out what Lars Ulrich, James Hetfield and Lou Reed had to say about "Lulu."