I fucking love it, and am actually just listening to it (no big surprise, because I don't listen to much else since I got that one).
The thing about the preview for me was that, although it didn't seem like much happening at all, everytime I got on the internet I found myself going to Youtube and putting it on again. Good sign...
Bought it the day it came out in Europe and have been hooked ever since.
For me the songs just work really well, for what they are. Organic Hallucinosis part two they are not. But they aren't really trying to be, actually it seems more like a "less is more" approach to me. Which I think works pretty well, for some reason I can better distinguish each song from the others on this album than on the older Decapitated albums.
I also don't mind the vocals at all, but I can understand if they put others off.
I'd say you could just listen to the songs on Youtube for a few days. If you still bother coming back to it then, buy it. If not, it's probably not for you. So far it seems that some people really love it and some get over it very quick.