The first disc has nu-metal, industrial rock and techno. Mainly b-sides, but nothing too awful.
It's all about the score, babe. Don Davis builds on the themes and signatures created for the first film. His collaboration with Juno Reactor and Rob Dougan works beautifully with the on-screen action. "Teahouse" has good tribal hustle - Not quite Asian, not quite Aboriginal.
"Mona Lisa Overdrive" starts out with James Bond techno, then shifts gears (literally) into standard techno-stomp. Don Davis keeps an orchestral layer riding over the whole thing, but the beat is the priority. Trinity's motorcycle sequence has a nice angel-choir opening, to go with the "deus ex Ducati" shot.
"Burly Brawl" is one of the most epilepsy-inducing things I've ever heard. It gets that way when Juno Reactor takes the lead from Davis at 3:23. The layers of beat loops AND voices AND strings AND synth almost make my ears tired. Plus, the tempo speeds up about five times as the fight reaches its climax. It goes with the sweep of the "Matrix" films - trying to encompass *everything,* with varying degrees of success.
Davis' "Matrix Reloaded" suite is a great closing piece at over 17 minutes. You get enough of each part of the film that it doesn't feel rushed. There's enough time to ease in and out of the emotional changes in the movie. Zion has a military feel, the love story is more classical, and the Matrix itself has a more paranoid, minimalist style.
Disc 2 is better than the score of the first "Matrix." Logically, the "Matrix Revolutions" score is even more intense and rewarding. Where the movies were sometimes confusing or overdone, the music is good enough to listen to on its own. Specifically, "Burly Brawl" will make you drive at least 10 miles over the speed limit.