Thanks for your always appreciated advice Roger.
Tried the Duo Weed 28 cm yesterday, fully lit with 7,0 nocam sail and S-type 115 on reasonably flat water, a brilliant combo. Yet no problems with weeds where I sail but the spot I choose yesterday is shallow. Really satisfied with the performance of the fin; fast, controllable, virtually spin out free (if not landing jumps with loads of lateral side force) and compact in comparison to other makes. A drawback in comparison to a straight slalom fin is upwind performance, but that goes for all weed fins as far as Iím concerned. From what Iíve seen I can highly recommend Lessachers fins.