I agree with @DiggingDogFarm
I have the Apex. the ' kit' had a fixed number of stones you don't really need all of them for KitchenWear but they are nice.
Id say 1 ) ease of use ( once you study the video's and get the hang of it 2 ) reproducible bevels
it was worth the full price for me over the long run , as I could not sharpen my Globals very well "" free hand ""
I have two knives from Japan coming soon . Watanabe
Im confident Ill be able to pick the correct angle w the EP and keep them in tip top shape.