Had a listen to Slipknot's new EP ".5: The Gray Chapter" and here are my thoughts on the songs:
XIX (Intro) - Not much to say. It's an intro to the first song. Waste of 3 minutes on an already lacking EP
Sarcastrophe - This song does not belong on the EP. Excellent song. Sounds like something from Slipknot Self Entitled
AOV - Pretty good song. The riffs sound good and most of it is good. Slow/Stone Sour parts aren't so good
The Devil in I - Most have heard this song already. Not a bad song if you like Stone Sour, not so good for a Slipknot song
Killpop - The F&^%.... This is one terrible song. Kind of sounds like a love song.
The Negative One - Most have heard this one too. Don't mind this song, good verses but the pre-chorus "The lord of lies..." annoys me for some reason. It just doesn't fit with the song. The song feels like it never gets where it's going as well.
Overall I'd rate it 2/6. One point for one great song. Two half points for two half good songs.