The new dwarven waraxe Duerthuldor does not provide any weapon bonus, despite "Attack Bonus: +4" in the weapon description, and cannot take any permanent damaging essence without replacing the base acid damage property.
I checked both character sheet and the logs on PGGC.
This can be heartbreaking to players, considering the amount of effort that is required to acquire it (finding rare materials, a duergar smith with 52 DC and putting 480 crafting points in it) - it is worse than a bronze waraxe.
Edit: Unlike the base race, Durzagons' attack bonus becomes lower when equipping a dwarven waraxe (by 6 for a mining tool and by 2 for a Duerthuldor) despite having the Weapon Proficiency (Dwarven Waraxe) in the feat list. There is no displayed penalty when equipping the weapons.