Too many grey areas.
Seriously, I'm listening to that album you asked me to, and it absolutely varies between terrible and quite sublime. Once or twice I almost stopped it because I couldn't get into it, then a good song (imo) would come on and I gave it another chance. I'll have a review soon.
If I had to make a very uninformed comment about them, based pretty much only on that album (but you recommended it so I have to believe it's the high point of their career/typical of their output) it would be that they are kind of all over the place. One minute they're something like black metal, then what sounds like post-hardcore, then AOR, then hard rock, then .... it just goes on and it's too confusing. They don't seem to settle. Plus that guy's voice freaks me out, if it's him doing all those different styles and vocals. To my mind, they're trying to be all things to all men, and failing most of the time.