From the following article on the Sail Magazine website:
Although huge, full-roached mainsails have been the rule on most catamarans for years now, in real life we all know that many cruising-cat sailors don’t ever use them because they can be so hard to handle. A number of designers have responded to this fact in incremental ways—for example, by reducing mainsail size or specifying in-mast furling. But now veteran multihull designer Chris White has solved the problem completely by taking the bold step of eliminating the mainsail altogether.
read more here