I've listened to every album the band has produced since Leviathan, and this is easily my favorite Mastodon record to date.
Many of my past complaints feel like they've been corrected on this release. The band's material has tended to meander, feeling more like prog noodling than structured, driving music. Here, the riffs grab my attention and move the music forward. The lighter, drifting passages work to accent the music and provide some character without getting carried away the way they have in the past. The varied, proficient drumming is excellent. The production, as usual, is clean and well-balanced. Normally I'm a fan of gritty production, but for this type of material the clarity is a better fit. Overall there's a nice sense of flow to the record, where the songs fit together well and feel like a coherent, unified whole.
I'm still not a fan of the band's vocals. To my mind the clean-but-strained singing is easily the weakest part of this release. I found myself on several occasions feeling that this album could be the one that finally draws me into the Mastodon cult, if only the vocals were better.
So in conclusion, this is good. There are still some things bothering me, but for the first time in years I won't be actively annoyed when I hear people talk about how great the new Mastodon album is. Oh, and the cover art is pretty awesome.