One or the top sailors on the Hobie (atchu!!!MB) mentioned that he has been working with the factory to keep the Tiger up to snuff competitively. One of the main things that he thinks will work are newer rudders. Something akin to the Marstrom Tornado Rudders. I saw a Tiger in France with this set up and asked the skipper about the caracteristics. He said that it drives like a sports car with that rudder setup. He thought it drove like a truck before.
If you are looking for reasons to buy a new boat there are plenty, but I do not think that many of the formula 18 designs today are "off the pace". The Tiger is still sailing very well against the others. I think the best reason to get a new boat is to avoid putting too much into your present boat if there is trade in value. As mentioned before you can almost upgrade to a new boat rather that outfit your boat with new sails. This also has the advantage of getting another sailor into the class, who would otherwise not afford a new boat.
Each boat may have a specific arena that it will excel in. I think that getting a nice "overall" boat and sailing it well can get you the consistant results you should be looking for. If you are only sailing in one place then you can buy a specific boat that covers those conditions. Or if there are no other types of boats you can sail what everyone else sails.
As for the price of sailing in this class...you would only complain if you have not looked at what it costs to sail in some other classes. A brand new "high performance" boat in the price range of $15,000 to $18,000 is not too bad. We are running the I-14 Worlds out of our Yacht Club next week. I have asked them about what a boat runs and it is expensive, about twice what our boats cost to setup competitively. Along with all the rigging that goes on with that boat, I will take the Formula 18...but I would love to get on one of those for a day.
Later,
Dan