I`ve listened to all three albums plus some other releases by the bands as well.
First off Malevolent Creation, I really dug their first album
The Ten Commandments despite its very heavy Slayer and Kreator influences but the album had some great classic style Slayer riffs. I was expecting more of the second album
Retribution given that its leading the battle, its a good solid album and thats all I can say about it.
Next up Monstrosity (I wasn`t put off by the name) Anyway George "Corpsegrinder" Fisher is a great death vocalist but the album not as solid as
Retribution.
Best though were Nocturnus.
The Key is a concept album based around a sci-fi theme and despite having the prog death label, is really just a technical death metal album but a great one at that, the publicized keyboards don`t really feature that much but the guitar riffing is first rate here, but its the drummer and vocalist Mike Browning that steals the show here! I also listened to their
Thresholds album and again another great album with Dan Izzo on vocals, he actually sounds a bit like Max Cavalera
Malevolent Creation-2
Nocturnus-1
Monstrosity-0