The Pro has a bigger brighter ProMotion display. It has active cooling, larger speakers, more ports, longer battery life, better graphics performance, better keyboard, and a larger default storage option (starts at 1tb).
If the Base M6 is good enough processor for you but want a more "premium" product, then the base Pro makes sense.
If the Base M6 is good enough processor for you but want a more "premium" product, then the base Pro makes sense.