I keep reading about acrylic kilts and poly viscose kilts. Hmm, I thought they were the same. Can anyone help me out here? Does one have an advantage over the other???

Currently I have an acrylic SWK and it's great for the bucks. But, I just received an IoS kilt of 13 oz. wool, made in Scotland. Oh, the SWK can't compare. How does a poly viscose stack up???