Riffs upon riffs upon riffs. An atmosphere that very much matches the album's cover art. Amazing performances from the entire band. Disgusting and vile - probably a lot more that could be added, but it'd be better to just listen for yourself. Trudger's "Void Quest" has to be on your radar - especially if you love Mastodon's early, sludgy material.
I've been listening off and on to this album as a sort of comfort album for months now and I love it with all my heart. It's not my favorite thing in the world, and I don't think it's reinventing the wheel or anything, but holy shit it's so consistently good.
Riiiiiffffffffage. Low-key might be my favorite metal release this year. Sludgy, prog-ish, and super solid.