There's been alot written about Mastodon's new album, The Hunter. Here, here, here and here just to name a few.
Here's my brief take.
I chalk The Hunter up to Mastodon not wanting this piece of work to have to be so cohesive. Think about it: for 4 straight albums, they told a cohesive 60 minute long story, both lyrically and musically. The Hunter let them break free from that and just write, sing and play. I saw the Crack the Skye tour. At times during the first set where they played the whole album, they looked stressed to make it all work. Now they don't have to do that. They can play whatever songs they want in whatever order they want.
Sure its more polished production wise, but The Hunter doesn't deviate from their previous work musically, what's missing is that cohesive story that we have all gotten used to.