Overall, the lighting plan worked out well. We decided to err on the side of possibly having one or two more lights than needed - and having a very well lit area. 
In general, keeping the lights about 6 feet apart worked fine. They are closer together between the counter and the island, due to the layout of the arae. We needed to have two rows of them to light both work surfaces without casting shadows.
For recessed lighting, the rules of thumb here for an 8 foot ceiling:
- 5 inch lights
- 1 for about every 35 square feet
- On the edges, keep them about 1 foot back from the front of the work surfaces
- I would rather have more light fixtures at lower wattage. It may cost a bit more, but then the light is more even, and there are no shadows.
The two lights over the island make a huge difference with the pot rack. They light the island top, where the recessed lights would be blocked.
