In the discussions about hull fineness, the distinction needs to made between displacement mode and planning mode. Hull fineness is a big factor relative to speed and fuel efficiency at displacement speeds, it is not so much in the planning mode. If your goal is a pure displacement speed cat only, longer and skinnier, if you need more speed in shorter lengths then the hulls will need to be wider to have lift off and the ability to plane. Of course potential payload must be figured in for either design to insure the hull floats where the designer intended for a give draft. And finally how much living space is needed in the hulls? For me the ideal would be a design that maximizes fuel efficiency in the displacement mode with long narrow hulls, and offshore ride, with high bridgedeck clearance at the compromise of headroom if necessary, generous beam, and low CG. If you are in the business of building boats the question is, would there be a market? If your are building a custom boat and don't care about re-sale, no problem. Life is a compromise, there is not perfect boat.