It's and induval thing. I bought a pair of Soral's about 1980 and am still useing them. The only grip that I have with them is the soles lack support, it's like waring slippers everwhere. It often bothers me that everyone thinks just because there is a new insulation materials, it's better that the old materials. If you stick to basics dress in layers, including your feet, keep dry and it's easier to stay warm than to get warm. One problem is the felt liner in a pac boot can be removed to dry out, this can be a major problem if you have to ware them for a long time. One advantage with the newer insulation materals boots can be made thinner and have the same insolation value. Like many things you will have to make up your own mind. The 1/16 inch thickness sounds about right for a boot with 400oz. insulation.
Have fun in Hamburg, PA.