* 3D is harder to get started, but easier to work with once a character is done (since you don't need to remake the model each time)
* Setting poses up is easy, but you occasionally fight with the model to get a limb to bend right (moreso if IK is involved)
* The same creator can do things different ways with different models, making some tasks different (The orientation of a bone does affect how it rotates in local space).

And... on a more personal note:
* I have more fun drawing women, but 3d posing men. This is likely due to curves being easier than straight lines. Also... more interesting opportunities for creative blocking ^^;