It's actually not that bad now that I think about it. It's BaB is higher than a dragons zombies and its natural armor doesn't get cut in half
EDIT: Well, he gets +11 NA which totals to a 48. 31 base, +2 from the dex increase, and up to another +4 from incarnum defense so that's not bad. He keeps all of his feats and skill points. Now that I've taken a closer look, this isn't too shabby.