thanks for weighing in here. what you read on the subject, did it mention why? what i'm thinking (if i understood the Link Roy provided us) is that if the primary difference is "Delta has a 37% hollow void and 3D has a 20% void".
then do we have two different physical phenomenon at work here? what i mean is, obviously the water can't penetrate the "hollow void" [sidebar question: this means the fibers are "hollow", right? if not then my whole train of thought is barking up the wrong tree, and i can't see why Delta would be warmer when wet than 3D.], but the Delta insulation being more compressible, as water penetrates the fabric and flows through the insulation, does it adhere (as in adhesion) to the 3D & Delta fibers? if so, Delta being more compressible, might this not mitigate somewhat against the benefit of the additional hollow void volume (assuming 3D retains more inter-fiber air spaces since it's less compressible)? i guess if both were thoroughly saturated, then the only air left is inside of the fibers - in this case, Delta would seem to be warmer.
am i making any sense here? do i even understand the nature of the problem? can you shed any light on my confusion?