I'm one of the F16 sailors that disagree! John P who won the F16 GC this year also wires down wind to great effect.

If I am wiring upwind, I Will wire downwind, up to about 20kts(I fall off too much above that!!!), but if it is a small course or there are lots of boats, you need to be able to manover more and so wiring makes it too difficult to gybe quickly.

I've also sailed the EU Spec Inter 17 and would also wire SOMETIMES; but because the boat is 55kg heavier than the F16, you are almost supplying the same righting moment by NOT wiring on the I17 as you are when wiring on the F16.