Recently moved my 19 hunter to 24, haveing skinning and herb already from being 19 im not finding herb as usefull at level 24 mostly cus the scale of the haste seems diffrent and the heal is minor compared to the health pool diffrence.
Considering to swap out my herb for either mining or engineering.
To awnser your question, i would get skinning.
I'm trying to figure out for a 24 hunter what secondary profession to get. I have 225 engineering right now for the boots. But for secondary what is better: Herbalism or Skinning?