There's nothing new here. Most navigation is best done with a bottle and couple of glasses. Put whiskey in one glass. Pop the otherglass onto the compass rose, shine a light from above, and the cut glass will radiate light out every 10 degrees. No need for bretons etc.
That's a bloomin' big boat, tcm.
Are you cruising the broker's websites by any chance, thinking about . . er . . upgrading?
If this is a sample, I'm very impressed by your shortlist, and your purchasing power!
ah. I think it's the limit for family sailing (no crew) for all sorts of reasons. Below this 60/70 foot size, engineering, galleys and so on become compromised by space constraints, and costs. Above this size there's little point for a small crew - there's simply more of the same thing eg 5 double cabins and so on, and loads more hoovering and cleaning. More prosaically, I'm limited by beam to 6m incl fenders.
This'll blimmin teach me won't it! I'm getting a right grilling....