Being a professional multihull yacht designer (and a New Zealander), I'm inclined to believe the 1988 America's Cup races could be very exciting. I find the claims of a mismatch a little hard to swallow.
This opinion is based on extensive racing of multihulls against monohulls during an 11-year period at Brisbane, Australia. There is no reason why multihulls and monohulls cannot race together--and it is even done in New Zealand. Such racing shows that if any monohull is 50% larger, the multihull has a fight on its hands. Only in very favorable conditions could we beat a monohull twice our size and New Zealand's boat is more than twice the size of Stars & Stripes.
In ideal conditions, of relatively flat water, and 12-knot breezes, Stars & Stripes should win. But such conditions are not common off San Diego. There's usually a chop and the winds off-shore are light most of the time.
And there's another problem. To be competitive in light airs against a radical monohull, twice as big, you have to build a catamaran super light with a huge, oversize rig. Then it starts losing reliability in heavier winds, and greatly increases the risk of capsizing.