I feel that this album is closer to Heritage and Watershed than Pale Communion in song structure; there's a lot of random breaks where the music dips to levels where you have to crank the volume to hear it -- but as we all know, doing this is a bad idea with Opeth (Note: Opeth is NOT road music.) However, the songs here are better written than most of Heritage, and are on par with Pale Communion (an album which reached into quite experimental soundscapes that this album generally does not.)
I don't know if this is supposed to be a concept album, but it flows extremely well. There are no flat-out weak tracks here; just some "meh" moments that quickly shift into something interesting. Chrysalis is the heaviest track (love the name too), with Strange Brew having some equally crushing moments. There was one line near the beginning of Moon Above, Sun Below from the previous album where Akerfeldt sings very aggressively without growling -- that style is all over this album, and particularly in the two tracks I just mentioned.
But there's obviously some of that melancholy Opeth we all know and love -- Sorceress 2 and Will O the Wisp (I love the Damnation vibe of this one) come to mind. There's an Eastern-sounding almost-instrumental, too, which is somewhat new territory for these guys. I don't know what's going on in A Fleeting Glance -- neoclassical? medieval? -- but I like it. And Era -- which is heavier than anything since Watershed -- boasts a catchy-as-hell outro-chorus that is probably considered the "climax" of the album.
Overall, this is kind of a mix of the Heritage sound (without the unstructured, random songwriting) with the slightly-more-straightforward songwriting of Pale Communion. There are no growls, and unfortunately I don't think there ever will be again. This is not really new territory for the band, except for the heavier moments where Akerfeldt sings aggressively sans-growlies. The album is solid and definitely worth a listen if you're a fan of the band.