So let's just start with special rules for Chaos Dwarfs since they are completely new to me. There are three special rules that relate to the Dwarfs themselves and one special rule for their Hailshot Blunderbuss.
Resolute - If I'm not mistaken, I think this is the same rule that applies to regular Dwarfs where they flee and pursue 2D6 - 1". They say it's because the don't want to give up their position in the battlefield but we all know it's because their little stunty legs won't let them move fast enough.
Relentless - CD's don't have to take a leadership test to march whenever they are within 8" of an enemy. An okay rule but with leadership 9 for most units I think they would have been fine in most cases anyway.
Contempt - Basically they won't take panic tests when friendly units are destroyed or break within 6" unless it's another Chaos Dwarf or Bull Centaur unit. They ain't skeered.
Hailshot Blunderbuss - 12" range, St 3, Armor Piercing, Multiple Shots (D3), Hailshot
Hailshot - Doesn't suffer from Multiple shot penalties; as long as 10 are shooting from the same unit, they ignore long range or as a stand and shoot; if 20 or more are firing, they get the same bonuses plus they get to reroll failed To Wound rolls.
I guess the question is which is better the Helglaive (18", St4, AP, and +1St in close combat) or the Hailshot. Perhaps we'll do some number crunching on that later on.