The concept behind the soundtrack to BLADE II is simple: take some high-profile hip-hop artists and some equally high-profile electronica artists, and have them make music. This idea is nothing groundbreaking, since the two genres frequently mixed in their early days (listen to Afrika Bambaataa if you don't believe me). However, if you think about it, the intricacies of their genre mean that electronica artists are probably better viewed as bands than merely producers, which is something most hip-hop artists aren't used to dealing with.
I say "most" because that description obviously doesn't apply to the Roots, whose lead rapper Black Thought knows how to divide the listener's attention between his rapping and the music of the rest of his band. It should come as no surprise, then, that his collaboration with BT, "Tao Of The Machine," is far and away the best song on the soundtrack.
Similarly, all of the songs that succeed do so because there is a sense that the rappers realize that they are working with fellow artists who have talents that at times deserves the full attention of the listener. Redman does a great job with "Gorillaz On My Mind," which is the best remix of Gorillaz' "19-2000" out there, and Bubba Sparxxx & The Crystal Method's "PHDream" is a pretty interesting take on a track from TCM's 2001 album, TWEEKEND.
Unfortunately, the flaws that do exist on this album are rather obvious. None of the tracks are bad, mind you, but some of them sound no different from ordinary hip-hop tracks (most notably "The One"). For someone who expects a departure from standard hip-hop soundtracks, this is a dissappointment.
Still it's a reasonably good deal, since only one track is taken directly from an album ("Right Here, Right Now" is available on Oakenfold's BUNKKA), and the good tracks are really, REALLY good.