NavList:

Thanks all for a really thoughtful and interesting responses. (Frank, I agree with the points you made in your typically comprehensive and expert review.)

I think, as I suspected all along, that it is the human weakness stopping any technical advance. Yes we can do better, but humans, holding whatever instrument  by shaky hands cannot. I’ll stick with my Astra IIIB which is as good as my old shaky hands can do and generally gets me within 5  miles of reality. My lunars, well not so good but so much fun, worth the errors. But the point is , this is fun and I suppose CelNav/AstroNav via sextant and then calculations, by whatever means, will never match modern GPS, which is pretty wonderful really.

I guess it is vive la difference!

Francis