Since it seems that there is still some interest in the US towards the F18HT class, I would like to make you known that the European class recently started a discussion about the introduction of the jib into the class rule.
See:
http://forum.mysnip.de/read.php?12763,1050889

On the topic I agree in full with Andy's opinion:
basically the introduction of the jib is going to make the boat faster/easier to sail in winds over 13-14 knots racing round the cans and in almost any condition in distance races, but for sure it is going to split the class: in given conditions only the sloop rigged version will win, in other the opposite.