The optimum crew weight is approximately 275 pounds. The ideal situation is for the majority of the combined weight to be the trapeze crew. There are many successful teams, however, sailing as light as 260 pounds and as heavy as 320 pounds. It is very important to keep the boat at the class minimum weight. This is more important than the age of the boat.
Older boats can be fast if set up properly.
A prime example is a 1983 boat winning the 1995 World Championships. The pivot bolt should be placed in the maximum aft and at the maximum lowest point per the class rules. The bottom leading edge of the board should be 6 inches forward of perpendicular to the keel line, max down, up to 12 knots of wind. In 13 to 17 knots, raise the board 1.5 inches to make the boat easier to plane upwind. In 18 knots, raise the board 3 inches so the leading edge is perpendicular to the keel line.