Rap is funny in that it's not consistently good, and there's more bad than good in a higher ratio than most other genres (IMO), but the good stuff is the best there is!
The first Death Grips album is heavier than pretty much anything that gets called metal these days. By far!
I did - the article devotes the majority of it's content to making fun of Dave Pirner (although, honestly, I would've gone with Burger King too), and it lists the bands for the other three artists. But it assumes the reader knows who Xzibit is.