Dave said, "...more like…". I take that to mean thicker and richer than a typical modern mahogany guitar, but not exactly like a rosewood guitar. Not that I have much experience Authentics or anything like that.

To answer the OP's question, I can't tell much difference between the new D-18 and the discontinued D-18V. It really comes down to the individual guitar and preference for neck shape.

The straight braced D-18 is going to be considerably brighter and often thinner. They tend to sound better as they get older, but still not my first choice.

The D-18GE will be bolder than either of those, thicker mids and a better bottom end.

The Authentic is another animal entirely, IMO.