A dry cut can make all the difference in the world. My understory is 3a, and my canopy is 3c. Because it's cut dry, with a light touch on the canopy, the canopy can blend in with the understory, and it just looks like it's all a mixture of tighter and looser curls.

I've also found that as my hair gets longer, the 3a areas are curling better, as 3a hair does when it gets enough length. (According to Jonathan Torch, it takes a minimum of three and a half revolutions for curl to be visually apparent.)
Peace,
Morgan

Baby Fine 3B, low porosity, normal density and elasticity
CGing since July 2008