Steve,

The answer is a little of answers A thru D. Over here there is no F-16HP racing to speak of. At the F16HP Nationals, only 3-4 boats showed and they all left early. The Taipans have two fleets (Annapolis and Tampa/Clearwater with 3-4 ea), but there are no F-16HP fleets.
Another problem is that there has been no F-18 racing to speak of. The F-18s had a good showing at their NAs in Michigan, but other than that, there are never more than 4 boats racing. 4 boats do not make a class.
At the Rehoboth regatta, Taipan builder and designer Jim Boyer chose to race his Taipan in the last half of the regatta in the non-F-16 mode (non-spi). Jim Boyer apparently showed some speed, but failed to beat the Nacra F-18, despite being a more skillful sailor than the F-18 team.
Overall, the F-16HP class has not been able to prove themselves to be "for real". At the last two major East Coast regattas in Hartwell, Ga and Rehoboth, De, there were only one boat attending each regatta. There was a lot of talk on the Internet about a F-16HP seminar by Boyer prior to the Rehoboth Regatta, but nobody showed. The F18ht class did have a seminar at Rehoboth with eight teams participating, but this doesn't help the F-16hp's cause. I recommend more time on the water and less on the keyboard.

Going sailing, so I must say adios!