I guess I will chime in here, the decision to design the Manta 44 without a flybridge was based on my experiences with a variety of motor yachts in this size range over the last twenty five years. Because of the proliferation of flybridge designs in monohull motor yachts the market has grown to expect flybridges as a "standard" feature out of hand. My observation was that owners often complained about getting up and down, separation from those below, and all of them ended up fully enclosing the area and piping in some climate control after the fact. Foul gear doesn't help much when it is 90 degrees out either! Needless to say the flybridge affects the center of gravity, overall weight, pitch and roll in a seaway, as well as presenting a lot more wind resistance affecting speed and dockside handling. Include the substantial added cost to manufacturing and there are a lot of reasons to eschew the flybridge. On the other hand with a single helm station the designer must insure there is excellent visability. One area not discussed in the comments so far is the fact that the extra weight of the flybridge requires widening the hulls for a given length to support it, consequently affecting hull fineness and fuel efficiency. I am sure a fine designer like Dick Vermeulen of Maine Cat resents being stereotyped as purely a "business person" when it refers to his concept of the best design for a cruising catamaran in this size range. I presume he like me has put an emphasis on seakeeping and fuel efficiency with his design, and with this as the criteria ,for a given length, a design sans flybridge is superior.