Gree: I think there is love all around <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />
I was helping out with the I-14 Worlds and was impressed by the speeds they take those things downwind in a blow. If you think you are using them for marks when the wind is up at 18 knots, I would say you have to catch them first. That was the I-14 and the Aussie 18 are faster.
I think around the course, with wind, the Formula 18 would win. That is only because of the upwind though. Maybe just barely, or not, over the Aussie 18.
Dan
When they are on the same race course on Sydney Harbour the F18's take line honors in most breezes but there is not much in it.
Tiger Mike