He can't get enough armour - once he has the crown, you've got 15 points of magic items allowance to play with. That will get you to maybe 4+ armour (Enchanted Shield) or a 6+ ward. He's still a T5 W4 character, and the ability to issue challenges will probably count you in good stead.
The reason I think people might be dismissing it is because at his points cost (and you have him at 425 points), you need to be playing a game at at least 2250 points to get a Butcher or BSB into your army. Players like the Hero choices. Don't get me wrong though - that sounds like an awesome choice to see on the table.
(I'm not sure where you think he's healing wounds from. It might be tricky to take a wound from the model but he'll never get them back.)