I first heard a few songs from PES, Kings Of The Carnival Creation, Puritania and Hybrid Stigmata, and loved it. But because I was at that time very little and used Limewire to download songs, I managed to download a few songs from For All Tid and original Stormblåst and nothing newer, listened to them and thought what the fuck. I didn't like them at all, so I kinda just listened to the couple songs from PES. Then I got by accident my hads on some later production and did some research and "found" the band again. I now have every album they hav , and the two best ones are IMHO PES and ISD. The newest one just has something in it that I like. But Kings Of The Carnival Creation is still my mos listened Dimmu-song.
Regarding Shagtath's vocals, I think the new vocals are better than the very first ones, but now with ISD they've come to the point where he's learned to sing them too well. He can do it without any difficulty and effort and you can actually hear that. It sounds a bit too relaxed and casual, so much that the lyrics themselves are actually quite easy to learn even without having to read them from somewhere.