Maxine - I can tell you a little about the sailing characteristics of the NZScow, which has this in common with the Chappelle design: square bilge, wide flat bottom and shallow draft.
I built a replica NZscow many years ago, it was 33 feet, rigged as a gaff schooner and had a large centreboard and a barn door rudder - and the point of difference with a NZScow is at the forward end where the flat bottom transitions into a vee, resulting in a somewhat bluff "sharp" bow. A large fleet of these vessels operated on the New Zealand Northeast Coast in the 19th century, some of the larger ones also engaged in the trans-Tasman trade.
My replica boat was built fairly heavily, and was not particularly handy at maneuvering in a confined space. It sailed quite well on all points, especially (of course) on a broad reach. It needed a fair bit of sail area, but could carry it, being very stiff. Sailing to windward, the old scow skippers knew "not to pinch her" but to ease off a little and maintain boat speed. She was remarkably dry when heading into a chop - the advantage of the "developed bow" perhaps, and the flam given by the NZScow shape.
The scow is not a yacht, it is a boat. If living aboard and accessing solitary, shallow reaches, one can rejoice in the fact. Mine was not prone to rolling or pitching, and being very heavy did not have a "quick" motion either. The biggest single disadvantage of the scow, as a practical boat for coastal cruising in sheltered waters - is the difficulty in getting at the bottom, for antifouling etc. On his triloboats, Dave Zeiger uses copper sheathing on the bottom. I have found that keeping the boat in a tidal creek obviates the need for regular haulouts.
I hope that gives some idea, and perhaps some of these remarks will also apply to the Chappelle scow. For further information I suggest you check out Dave Zeiger's triloboat website. The triloboats appear to be lighter and even a little shallower than the NZScow (and, I imagine the Chappelle scow), and I can not make a comparison. However the triloboat website includes some video clips of Dave Zeiger's boats sailing. They look good to me, you can draw your own conclusions.
One more thought: the paradigm of deep heavily ballasted hull (for stability) does not apply to the scow. No ballast is necessary, and they are very stiff. Not that they sail like a catamaran, but think catamaran for stability - high initial stability (and also, I suppose, quite stable upside down, though I can not imagine my scow ever capsizing due to pressure of wind.) One proviso: the hull must be kept dry. If water gets in, the vessel then suffers from the "free surface" effect and quickly becomes cranky. That lead to the demise of more than one of the old commercial NZScows - which generally carried their heavy cargoes on deck and frequently sailed with decks awash!