The great weapon and the dark blade do not stack.
The great weapon is a two handed weapon which gains its strength because it is wielded two handed. As such, you cannot use another weapon while you are wielding it.
So, by using a great weapon you are also denying yourself the possibilty of getting a 2nd attack with 2 CCWs.
In answer to your query, no I don't think many folks use them, simply because typically on an AC or IC you want to have a power weapon/fist/equivilant if they are tooled up for hth.
About the only really useful way I can see using the great weapon is with a DP stature as you yourself stated, but only if I was:
A) Strapped for points.
B) Really liked the look of the model.
Because you do lose the postential for another attack and there are so many better weapons to be had.
If It was possible to equip actual squad members with a great weapon, then perhaps we might see it occaisionally. As it is, its kind of an anomoly.
The great weapon is a two handed weapon which gains its strength because it is wielded two handed. As such, you cannot use another weapon while you are wielding it.
So, by using a great weapon you are also denying yourself the possibilty of getting a 2nd attack with 2 CCWs.
In answer to your query, no I don't think many folks use them, simply because typically on an AC or IC you want to have a power weapon/fist/equivilant if they are tooled up for hth.
About the only really useful way I can see using the great weapon is with a DP stature as you yourself stated, but only if I was:
A) Strapped for points.
B) Really liked the look of the model.
Because you do lose the postential for another attack and there are so many better weapons to be had.
If It was possible to equip actual squad members with a great weapon, then perhaps we might see it occaisionally. As it is, its kind of an anomoly.