to insulate or not to insulate

[Ely]

Attic 'wool' (glass, rock, etc) insulation is about half has good an insulator as Celotex - so you only need about twice the thickness when choosing wool.
Since it can be shaped easily around feeders and into voids beyond dummy boards, it certainly is useful - but its not as good an insulator as a similar thickness of foil-faced insulation board of whatever brand.

Problem is handling it and all the tiny shards of glass