It should be smooth and non jarring upon contact with the board. Anything that makes me realize the knife is there and working against me is counter intuitive. Instead of having 4" of dead flatness, bring the heel up like 1 or 2mm (I don't know the exact measurement it should be over that distance) over that 4 inches creating a minute curve. Think of looking at the horizon. It looks flat, but you know it isn't. Don't go less then 50mm height at the heel. That's about right for me anyway. I like a convex grind on the sides too for food release as it helps with the "thoughtlessness". As far as the tip goes, do what you like as long as it doesn't "bird beak" back down.
Hard to explain this stuff in words sometimes because they are the ideas and feelings of a user, albeit an experienced one, and not a maker. I hope I can explain myself clearly enough to be helpful.