PLEASE KEEP IN MIND!
If you are a new sharpener you are certainly not getting 100~ straight off the stone so you WILL see an improvement from using 6um after sharpening. For an example of how sharp this knife was please see the values I extracted from the Bess sharpness scale below.

250-350 = New High end cutlery edges
150-200 = Utility Razor blade
25-75 = double edge razor blade

Factory new Spyderco usually test around 140-170 for me.

Summary of my thoughts
6um is great for maintaining a dulling blade & mirroring.
Sub 1um is great for pushing for ultimate sharpness.