The 24 was the most competitive class but not it appear the F/C28R is the dominate class. I have sailed on one 24 and it was a little wet but spray was the main source. Its fine in big wind if sailed properly. It can not be sailed like a sled...none of these boats is a sled. I would try to crew for someone in your area. This is easier than you think because most times the skipper is looking for a crew.
As for the F25c -IF BORED NOW DO NOT READ!!! The F25c was made in molds by Colorado Composites who was a subcontractor to MPG Marine. A strict layup schedule and check list were followed on all 48 boats. The molds were vacuum bagged then the different pieces were put into a custom oven and baked. Most were partially assembled at the factory to the extent that the bulkheads, forward bunk, amas, hinges,etc were installed by the eight guys in the crew. Some of the first had fair to poor prep and the paint [usually Awlgrip] developed minor problems. There is little head room. There have been noted problems with the balsa core when boats are left on the water. If the boats are removed and allowed to dry out they do better. I don't know of any kits that are unfinished now. As for speed this tri reacts directly to the abitity of the crew sailing. Spray is less of an issue on this boat than the 24.
The F28R is a one design class that is campaigned in several areas. Its alot roomier inside than the 24,25c and the deck is more flat. If you want one design this is the way to go for now. Some of the top guys are racing this tri at Key West.
The C31 1D is also a one design class with measurement/ weight certificates while the F31R,RS,etc are more or less grouped together. This boat gets some spray as well but less than the others. When looking at them side by side the 31 appears awesome.
As far as awesome goes the F33R and F35c are it in my opinion. I inspected an F33R made in Austrailia being assembled in Houston and have seen pics/videoof the F35c. These are state of the art Farrier tris that when seen in person literally increase the blood pressure by 30 point...
But when looking at what all these cost to buy and maintain you should research this thoroughly.
Alot depends on where you are going to sail as well as how many boat bucks [1 boat buck =$1,000.00] you can spend.
I would look into the new F22 on the Farrier Marine web site. This tri is being built around the world by several people.
If not interested in that new age tri [F22] I would look for a starter F24. If you want something bigger after a couple of years they are generally easier to sell/trade in. Many of theres have been totally redone and some never have been on the ocean. I saw one on Lake Ray Roberts last month that was almost perfect.
fair winds,
thom