The song is fabulous. The raps and verses are strong and the chorus is nice and smoothe. Each member and each verse is very distinctive, easily united through the consistent beat. It's well spatialized and makes good use of harmonic double-tracking (especially Kangnam's parts). I like the mention of movie vs band, and how after that point the crippled hospital-bound ones get to stand up.
M.I.B has traditionally had a bit of trouble gaining a following, mainly due to the fact that they're trying to popularize a genre that's not terribly compatible with the largest spread of Korean Music. Rap and HipHop is typically kept Underground, I really like that they're bringing it to main-stream attention because the Korean Language really is just built PERFECTLY for rap. There has been an argument that M.I.B's lower popularity stems from the fact that they aren't Idols but that is completely bull. First of all, they are Idols, regardless of their feelings on the matter. They're individually contracted by a talent company and create music that cannot be played live without an MR backing track. They are Idols. (Note, being Idols has no bearing on their musicianship whatsoever). They are in an unpopular genre with a company that is not willing to push their promotions to extremes. Simple as that.
They are gaining a following, and a loyal one at that, and with this release they'll probably pick up a good number of new fans. The MV is interesting, and fun to watch, even if it's not an overly impressive or engaging story, and the song is very catchy and well produced. All in all it's a solid release.