Best combo of traditional lines & sailing ablility
I would not say that traditional looks and reasonable performance are mutually exclusive but in many ways there are conflicts between the hullforms found on traditional boat above the waterline and the hullforms that are understood to offer superior performance below the waterline.
When you look at the waterline shape of a traditional working watercraft, the entry was pretty full, the beam comparatively narrow and the stern fairly fine. That is a shape that makes sense when you need to carry a lot of weight, when you have minimal stability, when you have an inefficient sail plan, and underbody and when speed is less important that cargo capacity.
With the ability to produce efficient sail plans, enormous stability relative to drag, and lighter construction, the hull form of choice has a comparatively fine entry, has its center of buoyancy quite far aft, and a compartively flat run that terminates in a comparative wide transom. To prevent the kinds of bow down trim changes that were typical of early higher performance boats the topsides on modern boats are very carefully modeled to minimize heeled trim changes.
Placing a traditional topsides on modern underbody is essentially placing an eliptic top on triangulr bottom. They do not align and it results in a mix that is bound to be trouble when heeled.
It is not that there have not been some reasonably successful blends of traditional and modern. The Alerion Express, Ericson Independence 31 (31c), and to a lesser extent the J-32 fall to mind, but it is hard to successfully blend the most current thinking with the gentler ideas of the past.