Spinnakers on beach cats in 1988 were pretty "radical"- I watched my old video of the 1988 (1989?) Worrell 1000 and it is very interesting. Most of the spinnakers were flown off a bridle line between the bows but there was a Hobie 18 with what looks like a Flying Scot spinnaker or some such flown off a pole!
Greg could (and I wish would!) jump in here and provide his perspective but last I talked to him he admitted the spinnakers keep getting flatter and faster.
When we first proposed the class Greg wanted us to use a 21 sqm. spi (same area as an F18) since the European handicap "hit" was the same for a spinnaker up to that size and at that time the thinking was bigger was better. I own one of those original 21 sqm spis. and another original 17 sqm spi which is what we decided to go with since the 21 proved slower (it's now on my Freedom 21 mono!!). That is back in the "bag" days when the spis were launched out of a bag on the tramp- the Inter 20 had the infamous "toilet seat" snuffer at the end of the pole but that really cost you upwind! Then the T guys developed the midpole snuffer so I coughed up a lotta moola and got one of the original Guck CF snuffers. All these developments helped make the spi more manageable and faster around the (short) course- a tramp bag is still faster in distance races (check all the old Worrells) since it's lighter, simpler, more foolproof and less windage/drag.
Jim didn't like the spi due to the complexity and cost- and I still remember when I first saw him race the 4.9 sloop with his 14 y.o. daughter in Ohio against the "latest and greatest" Inter 20 with spinnaker and he beat the Inter 20 Boat for Boat around the course!! This without a spi on the Taipan just the jib and going wild on the downwind in big wind and waves! I don't want to embarrass anybody but the Inter 20 sailor was a well known NACRA sailor.
Also, at that time the Taipan was doing very well in Aus as an OD one up and two up boat so adding an "F16 class" was not felt to be an obvious good thing there. Thing was, at the time we were developing and conceiving this formula class a "spinnaker" on a cat was the "hot ticket"- any new class without one was deemed "old" and we definitely felt it was the future so we included it. Rick was a staunch Hooter fan then and put a Hooter on his 4.9 but Jim felt the 4.9 could not handle the high forestay loads so basically the use of a Hooter on a 4.9 at that time nullified your warranty, but Rick could get the boat to go with a Hooter! The Hooter being flatter than the spis of that time was probably ahead of it's time and more similar to the "newer" spi shapes.
We met a lot of resistance and criticism in the early stages here in the US as the F18HT had also just been "introduced" into the US and was heavily marketed here as the "next great thing" with many rock stars being compensated/convinced to be involved in that class. They felt their "concept" of a high performance, light, 18 footer with main and spi was much superior to our smaller, slower, less "techy" cats. Our first F16 Nationals was held in conjunction with their Nationals at Rick's place and they laughed at us then because we had so few participants compared to them. Of course all our boats "survived" the regatta except the one that was damaged by one of the F18HT's while they had multiple breakage problems. I think it's a testament to the veracity of our concept that F16's now greatly outnumber F18HT's here in the US and our numbers seem to be growing. I agree with Wouter we are sort of an interim fleet between the more all out racing two up F18's and the one up "A" cats- and that's FINE! That's our "niche" as we envisioned it. How the class will develop and grow in the next ten years is anybody's guess but from a handful of Taipans in the US, a few Stealths in Europe and some renegade Taipans in Oz the current state of the Class and it's growth would seem to indicate we are and have been doing something right.
I would argue that the Viper is a great sloop F16 and probably optimized as such and I suspect someone may come along (if Stealth has not already?) and someday produce an optimized uni F16- since the loads are lighter, like an "A" cat, everything can be downsized and rearranged- the hulls could be smaller volume with less windage, sails can be flatter, shrouds etc. can be smaller and lighter, etc. It may be that what it really takes for sloops and unis to be nearly identical in performance around a course is a lighter, "smaller" uni F16 with main and spi and a heavier, larger, more robust sloop F16. This is not what we as the originators had in mind, intending the boat to be able to do "double duty" as Timbo stated- I got tired of going to regattas with my NACRA 5.0 and my young sons and wife, all of whom told me at one time they would race with me only to get there and find it was too hot, too cold, too windy, not enough wind and boring, etc.!! I had to dredge up crew or try to sail to a crazy rating on that boat by myself! The market will ultimately determine where our class goes directly or indirectly. I do not really mind that H**** or N**** do not want to "play" in our sand box as I have had enough of both of these manufacturers try to take complete control over "their" classes- telling you to buy cr*p sails, changing the rules/equipment when it suits them, etc. If that's what they have to do to stay in business then that's fine, but as a "customer" I don't like that policy personally but that's their choice. We, like the "A" and F18 classes, are sailor, not manufacturer, controlled. Of course the real point of all these discussions is that without "product" (ie new boats) we will become just another Dead Boat Society. But you have to remember- When the three of us came up the concept and started this class there was not a SINGLE "optimized" F16! WE created an obviously viable concept and a demand and THEN manufacturers, seeing an opportunity, stepped up and started making boats (THANK YOU STEALTH! I believe they were the first to actually do so-). The sailors then "sold" the boats and the class by sailing them and having fun both one and two up!
Wouter, Phill and I have devoted countless hours/dollars/effort to the class in the beginning- we were all a lot younger then- and it's been great to see other people take over the reins and keep this thing going!
I agree with what someone said- the best thing you can do to support the class is get out there and show the World how much fun sailing an F16 is, regardless of whether it's the stiffest, fastest, most expensive, etc. and whether you are just having fun or racing!

Kirt