Images with grey, dull, overcast skies tend to look bland and uninteresting as it just produces a wall of white - although sometimes that can also work in your favour -  I personally like it in the image below as I'm using it as negative space in the image.
Dramatic skies look fantastic in black and white!  Images with grey, dull, overcast skies tend to look bland and uninteresting as it just produces a wall of white - although sometimes that can also work in your favour -  I personally like it in the image below as I'm using it as negative space in the image.