I'm unwilling to seperate the two.  They are variables in the same equation - it's the answer that matters.  And the only answer that matters is "is the client statisfied".

Internal processes can be efficient - routing between jobs to not backtrack, billing processes, procurement and the like.  The back office has to be efficient to control overhead.

The front of house has to be as calm and pleasant as possible.  The process of tearing someone's house apart is a stressful experience.  It's "effecient" to to come like a bull in a China shop and run the project with ruthless execution.  It won't be effective because the energy exuded by that methodology will transfer to the homeowner and raise their anxeity.  It's loud, messy, and sometimes smelly -but effeciency is at the bottom of the list when dealing with the client - their experience is what I'm focused on.