This is my favorite album from Suffocation. Along with demo in 98, which sounds even harder, but less distinguishable. Pierced from Within (1995) is hard and distinguishable. Now it represents classic album of Americal death metal(technical and brutal type). I personally learned some songs to play on guitar some decade ago, when I was in a metal band. Really hard to play and properly constructed.
The same could be said about the structure of songs. Complex and complicated. Still remember Suffocation mania from late 90's. The best band in their own kind. Of course there were other similarly good (for example Cannibal corpse, Immolation, Sinister, Dying fetus, Death, Napalm death, and many others ), but Suffocation was somehow seen as the one with the earliest succesful attempts to play hard, complicated, technical and still recognizable sound. Straight first 30 seconds will let you know, that the material is heavy and deep.
I also remember liking the solos the best from all death metal bands. Very distictive and fast. And as I walked around in the metal circles, I hear that many others consider exactly this band to be the break-through one (when it comes to style within death metal).