I used Propspeed on my last haulout. It worked for almost a year, but ultimately became fouled and hard to clean. I am going with Velox this year after reading several good reviews. It has to be better than nothing. I don't mind diving on the boat every month or two, but the hull doesn't need cleaning that often. We'll see how this goes...
Put on a new FlexoFold prop (18x14) on my Bav 44 this year. It was a little difficult to put 80 grit sandpaper to the new shiny prop, but that's all part of the prep work.
Cheers,
Jake