The twin keel design is slower, but it creates a very stable and versatile vessel.
My father-in-law sailed a British-made 24 ft. Westerly around Cape Cod for many years. It had twin keels. Because of its shallow draft we could leave Sesuit Harbor at any tide level without fear of running aground.
Another nice thing about the twin keel design is how easy it fits on a trailer. He used to tow "Neirid" back and forth to the Florida Keys every winter behind his pick-up and it rode nicely.
Another thing that I recall about his Westerly, which may have absolutely nothing to do with the keel design, is how much space this boat had: 6 ft headroom, adult-size head, a galley, enough room to fit an Atomic 4, and enough berths so that 4 of us could comfortably spend weekends aboard.
I think the twin-keel design has many practical applications for the U.S. and the Bahamas, especially where water depth is an issue and you're willing to trade speed for stability.