Yes, the sound quality is poor.
And yes, the songs are long and very complicated.
But get your head around the complexities, get over the poor production, and you will hear this album for what it is - Metallica at their best.
Master Of Puppets may get the reviews and the hype, yet it includes The Thing That Should Not Be, Sanitarium and Leper Messiah, three very forgettable songs (by Metallica's standards). The Shortest Straw is probably the worst song on 'Justice', and it is twice as good as any of those three songs.
Having said all of that, if you feel a need to read the reviews in detail before purchasing then your mind is probably not open enough to be able to appreciate the music!