Michael Daly wrote:

but the main reason manufacturers stopped making polypro
is that it lasts so long that they can't sell replacement garments.

Polypro lasts long (I still have some that is usable and was purchased
in the '70s) but it can't hold an antibacterial treatment. Hence the smell
associated with polypro. That is a major reason for the popularity of
polyester fabrics over polypro.

The anti-smell chemicals added to polyester only last several launderings,
so I don't consider this a major advantage. As boaters, when our garment
smells bad, all we need to do is rinse out the underarms.

You're right about comfort - polyester is not not as rough and
scratchy as polypro as a base layer.

I experimented with nearly equal-weight Polypro, Capilene, and Polartec.
The results were approximately as follows:

Weight Weight
after after
dunking wringing
Polypro 4x 2x
Capilene 6x 4x
Polartec 6x 3x

Polypro is definitely the best thing to wear under a paddling jacket
in conjunction with a wetsuit. Inside a breathable drysuit or drytop,
my recommendation is Polartec PowerDry, an engineered polyester fabric.