I finished up my test Bane Thrall grunt last night, and decided to sleep on it and reassess how I think it looks today. I decided I'm happy with it, and will be painting the rest of the unit to this standard.
I kept the highlighting techniques to a minimum as I don't want to spend too much time on each model in the unit. In my experience, that's how I lose my painting momentum - so with my squads I try and keep a "Just Get Them on the Table!"mentality.
Highlighting on the cloaks do absolute wonders for the models though, so I plan on coming back to add that detail some time in the near future.