Here's a link with elapse times with 2 F16 uni rigs and 1 A-cat (I realize that's not many!):

http://www.catamaranracing.org/results/commodores_04.htm

Here's another result (one F16 uni, one A-cat):

http://www.catamaranracing.org/results/whitecaps_04.htm

Of course there's always a story behind every race result, like me and the other F16 capsizing once or twice, competing against a former olympian (Finn), a broken tiller extension, etc. But overall we've had a great duel between the a-cat and us, him taking us upwind and us passing downwind.

At another race this past summer we started 5 min behind the A-cat start. I noticed a wide disparity between the fastest and slowest a-cats. For what it's worth, we (F16 unis) caught and past 1/3-1/2 the a-cats on the downwind leg. On the other hand, the fastest a-cats were on the beach showered off by the time we finished (ie Pete Melvin).

Summary: A-cats and F16 unis are remarkably close around a course. A skilled a-cat sailor would certainly beat me around a W-L course; a sailor with equal skill as me on an a-cat would have a difficult time beating me on an F16 uni; a sailor with excellent skills on an F16 would likely give any a-cat a good run.

...F16 sloop is another story--definitely faster in my experience than the uni rig.