Well, I just downloaded it a few days ago and... well, it's interesting, to say the least. There's some great techno/8-bitty remixes, plus plenty of copious sound-effects, and I can understand the raps (they wanted to include plenty of different genres--and some people who play videogames do like rap)...
...But whoever made song #9 on Disc Two is an absolute idiot. That was the most foul-mouthed, bizarre thing I've ever heard on something purportedly related to Mario.