This article shown a couple of days ago on the FF rudder is very true. I changed my original rudder (unbalanced) to a modern balanced one and it transformed the feel of the boat, being much lighter on the helm and giving much better feedback. A secondary benefit is that at high speed the old rudder could cavitate and stall out, leading to loss of control and a wipeout, which is ultimately what broke it. I have never had this problem with the new rudder, which is also thicker in section and has a much better profile than the old, thinner blade, so the water flow stays attached much longer.
In my case, the rudder was oredered through P&B and I sent details of the angle of the rudder post, length etc.The resulting made to measure unit fitted exactly and, as I say, works very well indeed.