The only reason I would hesitate to recommend this to anyone who even has a passing interest in Metallica is the sheer length of it - four hours!  It's an awful lot to digest at once, or even in pieces, but of course if you love this band, four hours is not an inconvenience, it's a BONUS.  It's also a great insight for everyone interested in the recording process.  The second part of the disc covers the band on tour, which is a scenario covered in countless other rock documentaries.  But the first part, covering the recording of the "Black Album" offers some intriguing information into what a producer actually does, and the producer here is one of the most legendary in the business.  Bob Rock probably ranks only behind "Mutt" Lange and the late Bruce Fairbairn on the list of sucessful hard rock/metal producers.