Overall I love each of their releases.
Fall of the Idols self titled release is pretty damn good. Production sounds more "robust" than The Séance's, but I feel this is a benefit in many ways (everyone has their own preferences when it comes to this, so I'll go no further than this). The songs aren't as bleak sounding as many of The Séance's are, but you will definitely hear some mournful vocalizations when you hear songs like Crawl Back in my Hole or Vile Matters. The thing that will really stand out though is that this release is pretty uptempo; a good comparison for track speed would be At the Birth of the Human Shadow. The whole release is sophomoric compared to there other main releases, but I think it is still pretty damn good.
The Womb of the Earth is, in my opinion, a fantastic album – but it is an altogether different monster than The Séance . You won't get knocked in the face with the shear bleakness that you will find from tracks off of The Séance like An Age Comes to its End or Nosophoros, but it is there. Songs tend to have a repetitious form, but this ends up making the eventual refrains sound very pleasing. I only found maybe one or two tracks that weren't as well written as the rest of the others, but most people I know tend to agree that you can never go wrong with these songs: The Pathway, Ungodly Thirteen and Keep Wandering the Night. These tracks seem to have elements that were expanded upon in The Séance (you'll definitely hear some variations of riffs found on that album).
The Agonies be thy Children demo is a good listen to see what the band came through, but the only benefit is to hear Beneath the Burning Sun, which is an interesting song in that it contains some awesome foreshadowing.