I have a cross question. Which do you use to complete the cross, u or D? I find it much easier to turn u, but it is harder to look ahead. D is easier to look ahead, but I have to re-grip to turn the D face.
I almost always use u, because it is almost a rotation and it allows me to find some F2L pairs. However, I will use D if I see a pair and don't want to mess up where it is at.