Honestly the best thing I've found for checking is a loupe, mines x60 but ya can get up to x100 and ya can properly see inside the trichs for cloudy Ness.
As for cloudy % that depends, ime having clear and cloudy trich leads to a more energetic high, whereas cloudy with a touch of Amber gives you more balance and more mellow high, and waiting for lots of Amber will give you more of a "jaysus I'm mashed" kinda stoned.
I think it's to do with the concentrations of cbd, thc, and terpenes changing throughout the ripening phase of flower.
Edit; Sidenote, I prefer lots of Amber and tho it's a pain waiting another benefit is increased yield. I've found that those last 2 weeks when the buds aren't gettin any bigger and leaves are dyin, the buds are actually still gettin denser on the inside