Just bought a pair of these in 17cm to go on a 85L ish custom twin.
I am running 7.5 inch (19cm) JP G10 fins but getting caught up on weed on slow speed days and struggling to clear it.
Sailing Dutchies (cross on, small irregular waves) mainly but also trips to better locations.
Used with a 5.3 KA Kaos for a couple of sessions so far and placed further forward in the box to put the centre of the fin in the same spot as the JPs. The fins are well finished and very stiff with good thickness in the base. They come with fin covers and screws/plates (US box). I could not find weed twins locally and they are well priced at $134 US (plus shipping) a pair.
Upwind performance is not as good as the big JPs but perfectly adequate no problem with letting go as you push upwind.
Turn much tighter on the wave than the big JPs and generally performed well. Typically the two days that I tried them were low weed days but want to be ready for winter.