I know nothing about Coroner so I know nothing about how this is apparently an evolution of their earlier sound. So I can only go off how it compares to other “thrash” metal from the era.
The sound is polished and technical when they are playing straight thrash. It’s definitely nowhere near as fast as you might expect for “thrash” – most of the time – but it also has considerably less groove than you would think for something that is often quite deliberately paced. (So I guess there’s a bit of a doom metal vibe, only the playing is quite technical for that.) The playing is stellar, though, even if it isn’t always as fast as you might think it should be. And the solos still manage to shred.
There are weird little touches here and there which do not fit in most conservative idea of the genre. Acoustic guitar for example – a thing Metallica did but not too many others – and keyboards, and a few samples. I think the art/prog influence has perhaps been overstated but there’s definitely some ambition here. I would prefer more but it is 1991 – I’m not sure how many bands were integrating prog/art music ideas into thrash in 1991, a few but not that many.
The vocals are not great, as many have noted. But I think there were plenty of bad singers in the metal world in the ’80s. It was almost a way of distinguishing yourself from those terrible power metal cliches. Royce is like shouting quietly or something, and he’s caught somewhere between conventional thrash and actual death metal. But it’s not annoying enough for me to care.
The production is fine, it’s not amazing but it’s also far from the worst metal production I’ve heard from this era. (Can’t hear much bass, which is basically de rigueur for 1991 metal.)
Also, if you were ever wondering if the Beatles played rock music, this album has a Beatles cover – and it’s really not that different (and honestly not the greatest). So take that “Beatles were a pop band” people.
Anyway, I mostly enjoy this. I worry I’m overrating it slightly due to either a lack of knowledge of the progressive metal world of 1991 or because I was in the right mood, but I like it.