You should get it, i was pretty dissapointed since Mardraum, when they started to turn into progressive stuff. I sticked to the first three records, which are fucking great, you should definitely get that frost/fire/blood trylogy just as Ivar said.
Vertebrae is not the easiest record to listen to, but definitely an entertaining one, you can see that Enslaved are in a totally new direction. Clouds is a good song, as well as The Watcher, Vertebrae too.
You should give it a try.