When the apparent wind is forward, anything that presents drag without making power is going to slow you down, especially when you have a fast boat (like a cat). Wings are great fun for cruising and yahoo sailing, but I took them off my 18 for any kind of racing. Weight, air drag, and water drag. It's the main reason the 18 magnum and 18 carry the same rating - any increase in hiking capability is offset. Of courrse, that's all relative to the full-style wings.