There has been a huge wave of thrash bands in the last few years. While many of them just copied punky party-thrash in the vein of Municipal Waste, there are some exceptions. Immaculate is one of them.
I think it is the uncommon combination of high, clean vocals, fast and precise thrash riffing, and at times epic guitar leads (Atheist Crusade, The Immaculate Dead, Gutterthrash) that make this album so memorable. While songs like "Thrashark" or "Thrash Metal Avenger" are rather typical for its genre (fast, aggressive, less melodic), the almost 9-minute long title track is what makes me love this band. Beginning with the fast opening riff, the song leads the listener through an overwhelming number of great melodic thrash/heavy metal riffs before breaking down to a clean guitar part that introduces you to the second part of the song. An extended guitar lead follows, which I would simply call epic. The Maiden-like twin guitar leads just fit this epic atmosphere, and when you think it can't really get better, the thrash kicks back in. Godly.
Unfortunately, the rest of the album can't entirely keep up with the the title track. While some songs are just slightly worse (The Immaculate Dead, Gutterthrash), others are rather typical for technical thrash. They are still fun and great for banging your head, but not outstanding either (I'd give them 80%).
A nice surprise is the Fates Warning cover (The Apparition). When I read the track list for the first time, I wondered whether it would sound out of place, but it didn't. Especially on this track, the vocalist Mika Eronen shines. His high-pitched voice matches the one of John Arch very well, making this an excellent cover. Of course, he isn't on the same level as Arch, but he gets closer than most other singers would ever get.
For a self-produced album, it sounds surprisingly good. You can clearly hear all the instruments (even the bass!), and there is a good balance between the instruments, which is needed. The guitarists especially have some serious skills,as you can hear in those extremely fast-picked riffs. Only the vocals sound somewhat thin, but to me this is only a small letdown.
Conclusion? Get this right now if you are a fan of thrash and/or heavy metal and don't mind long songs or high-pitched vocals. The album is not perfect, but still highly enjoyable, and as there aren't many other bands (I don't know any...) playing this kind of music, it is a welcome change in thrash metal.