Dance of Death was a great album, Paschendale and Montsegur are both superb tracks, however A Matter of Life and Death was totally different. As far as I can remember, it has the shortest writing / production time of any album, mayber barring their debut. I think you have to put in that context, yes it is different from anything that has gone before, but does have a sense of 'immediacy', that makes it more 'human'.
El Dorado does'nt have as powerful hooks as previous singles, but will no doubt make sense in the context of the album.
Best album has to be Somewhere in Time, followd by Powerslave 8)