Also, and I'll try to post a photo if I can find my camera, would you put a can light over the sink if you were going to put a wood valance/apron between the two uppers on either side?

I'm posting the only halfway decent "full view" of our kitchen taken from the family room a while ago so you can have some perspective, but not all our lights show here. The space between ours varies greatly.
To answer your question re. the sink area- we don't have a canopy, but we have 2 can lights over our sink. Our goal was to have a can light along perimeter slightly in front of each cabinet. Once the ceiling came down and we took out soffits, we had double joists and waste pipes to work around so we had the electrician do what he could while maintaining some sort of symmetry. There was no way to center one can over the sink, so we put in 2 on either side of the joists to balance it out.
We did not do a can light in front of cooktop- the light in the hood has 2 settings and we find that more than adequate, plus we will have the 3 pendants over the island (this friday!)
What doesn't show in this photo is the other can next to the fridge (there are 2 over the recessed counter there, as well as three others in the area immediately after the kneewall this photo is taken through (to light up the eat-in table area and the cabinets/counter that we built into the kneewall).

My point is, despite plans, you may have to work around joists,etc. so keep an open mind. Before the cabinets went in I was stressed over the Swiss Cheese look that was our ceiling, but honestly it doesn't even phase me now that it's all put together.

Thanks labbie, that helps a lot. It looks like you did what we tried to do, and centered the light over the cabinet door or pair of doors.

Yes you definitely need one over the cooktop!! Or believe me, every time you take picture you will see a dark spot there.

We even continued our UCL across the inside of our custom wood hood (of course after the fact), so that the lighting would be more even. Even with this and the hood light on, there is a variation in color in the backsplash.

Lighting is an area I wished we'd spent more time on upfront. Suggest you add lights to your plan and post it and then solicit feedback. Include where you are putting your light switches! Also, please describe the lights you are planning on. I'm sure there is a big difference between 5" and 6" can placement.

We went with the CREE LED LR6's (CR6's? darn it, now I forget). The one that dims down to 5%. (Of course, bought the other kind first and had to exchange...). Really like the lights.

Furthest spacing is around 50", light to the left of the cooktop to the light centered over the cooktop. We didn't alwayds center the lights over cabinets but that's probably due to beam placement. Good luck!

We didn't put one in front of the hood. I have one centered in front of the cabinets either side of the range top and the one a little further out in front of the ovens. The hood itself has what I call my surgical quality halogen lights, there is a window on the wall opposite so it gets some natural light and the light over the island is right in front of the hood. I sure didn't need another hole in the ceiling.

I use my hood lights only when I'm cooking, and there is a noticeable column of darkness where the range is when the hood lights are off. The CR4s centered on the doors on either side of the hood seem only to accentuate the darkness of the range spot. I SO wish we'd put a can light over the range! I tried to take a pic, but the problem doesn't show with my dumb little camera. Or maybe it's operator error, I don't know.

We have a can light just to each side of the range hood. I decided that since our hood angles out fairly close to the ceiling that we'd be more bothered by a spotlight effect on top of the hood.

I'm not sure how recessed lights in the ceiling would provide much light to the top of the range itself anyway. Actually, there's plenty of light to see to cook, but the backsplash looks very dark if the under-hood lights are not on. This is only noticeable if the under cabinet lights are on, and the hood is off. Putting a can over the hood would not solve this issue, though, because the hood would be in the way. Our solution is to put the hood lights on if we want light there. Works like a charm.