This may be a very subjective subject.
Most winning boats don’t appear to fall into a particular year or builder category. Hulls although shaped the same do have differing reenforcements from one manufacturer to another but that also doesn’t show any pattern when it comes to race results. Often there are differences even within one manufacturer.
More posts will follow. I would contact Cape Cop Ship Building and get their opinion on this also. They offer a new DSI (has the attributes of a DSII) but may have some historical info on the optimum DSI.
http://www.capecodshipbuilding.com/site/daysailer.htm
Brad