Listened again today, and in reference to the other thread in GMD, I think this album is underwhelming because it doesn't have any 'moments.' Fortress and Kezia were full of those parts you knew were coming and anticipated every time, but I can't hear anything like that on this record. I also think that with the lack of harsh vocals his singing voice gets pretty grating. It was OK on the other records because it was offset by the growling and screaming, but I don't think his clean voice is strong enough to carry (almost) the whole album.
It's good, but not great. Which is a shame. At least live he's still singing the old songs with the harsh vocals, a lot of bands change the old songs to their 'new' style once they make a stylistic change (Trivium, A7X) and that doesn't really work out in most cases.