In researching a reply, I ran across an article that is possibly useful to some of the team here. It was for me...

Flyanglersonline Double Taper vs. Weight Forward

Years ago, the marketing thrust for the DT was it would last longer, i.e. when one end wears you can turn it around and use the other end.

Personally, I prefer WF because of the somewhat obscure point he made about less false casting with the WF. Its a critical factor in a lot of the fishing I do.