Keith,
You mention lack of sailors. This came up on the SA thread, I ran the numbers for the past three years, the F-18 class has doubled in size since 2009 while the N20 fleet has basically remained constant over that time. Right now I feel the N20 fleet is on the decline (lots of boats for sale). I think most of those sailors are buying other boats, likely F18's. The argument was made that the F18 boys don't want to run their boats up on the beach for a week. That may be the case but I think they either don't have the balls, or are financially committed to other events (World Champ's in Europe).
There are plenty of distance racing events in Florida to get warmed up for a Tybee, big issue is getting a boat down to the keys and back for a 2 day event makes little sense for most.
I am very sad to see the catamaran distance racing scene on the Chesapeake die, especially as I am moving back into the area and would love to do some of my favorite races on a fast beach cat (Governor's Cup, Down the Bay). After selling the N20 I was planning on buying a F18 within the year. With the move to the area and the lack of fleet, it makes much more sense to buy a F16. That leaves me with a dilemma-I would not hesitate to take an F16 out in any weather I have seen on the bay, and distance racing it wouldn't be an issue there, but its not a Tybee boat. I think a F16 could do a Tybee, if you brought enough spare parts to support yourself. I think the F18/N20/F20c are better boats for the race, especially if upwind in steep, short chop is experienced.