Lord Of Putrefecation is the earlier incarnation of Electric Wizard.
It's not too far off from the sound of Electric Wizard, the most notable thing being the tonality of the vocals. Excruciatingly slow, and I think the main flaw with Lord Of Putrefecation is that unlike Cianide or Mortal Remains or other great bands of this style is that they don't pick up the pace at key moments. A large increase in tempo contrasts very nicely with the slow moments, and increases the overall effect of the album. They did it midway through "At The Cemetary Gates", but a bit more would've been appreciated.
So while the Lord of Putrefecation half of this SPLIT is good, Mortal Remains outdid them on this one with their tempo changes (Excoriate and Infected being primary examples)..
Recommended tracks are:
Mortal Remains: Excoriate, Infected.
Lord of Putrefecation: At the Cemetary Gates, Wings over a Black Funeral.