I really enjoyed it, although it's not without faults the main one being the lack of time so we don't get the usual fleshed out characters. I think this hurts Aethelstan in particular, as he seems such a changed person to the one is series five. It's obvious he is under the spell of his lover/advisor Ingilmunder, who does a great job of exploiting the traits in Aethelstan's personality. But I do love the fact that there are obvious parallels to Aethelstan's journey in comparison to Uhtred's in the series. Not least the idea of discovering his identity as he quickly becomes King. The other problem with the lack of time is the fact that the journeys which the show was good at giving time too, are crazily quickly reached. But I don't know what they could have done about that with the time constraints.
There is a good mix of plot and a great battle at the end. I especially enjoyed the relationship between Uhtred and Edward's widow Eadgifu which was beautifully portrayed by the actors. It was cool to see Wirral become the vocal point for the battle of Brunanburh and the battle itself was very gritty and great to see it won by a smart tactic and shield wall! The ending was beautifully done, it's an open ending so up to you to decide whether Uhtred lives or enters Valhalla. I think he dies, but its a beautiful ending either way. It's not as good as the show, but I think it still works. I will miss this show Also, Aldhelm's fate, so sad.