I read this interesting article that illustrated the difference between processes optimized for flow efficiency versus resource efficiency. Maybe not obvious in that article why flow is cheaper (or same) cost as resource optimized but if we assume customer satisfaction is a great asset I think it is obvious which process is preferably from a customer satisfaction perspective...
Glad you like the post. When optimizing for flow efficiency first you tend to remove non value adding steps (yellow bricks). You also tend to lower the work-in-progress (WIP) and batch size and this will reduce extra work and costs to handle lot of work (or people in this blog post).
If you are doing product development focusing on flow efficiency also gives you a much better time to market.
/ Håkan Forss