Some calculations
I’m looking at this ketch to buy, and I was screwing around with the different possible sail configurations.
Here’s the chart:

SA/D Ratio is the sail area/displacement ratio. This ratio indicates how fast the boat is in light wind. The higher the number the ‘faster’ the boat.
* Cruising Boats have ratios between 10 and 15.
* Cruiser-Racers have ratios between 16-20.
* Racers have ratios above 20.
* High-Performance Racers have ratios above 24.
There are some pictures of this boat on my Flickr site.