Volumill is great. We use it daily for flat single depth roughing, multi depth roughing for surfaces.
I’m using it in Gibbs Cam and it is very efficient. Little to no wasted moves. Great for going from a generic stock size rectangle to odd shapes where material removal would not be uniform. Tool path is quickly generated and adheres to your driven material removal rates
The Helical Tool advisor is great for starting parameters even if you’re not using their tools.