In general I find it quite amazing how many designers/designs one can find on the Internet. It looks like most designers now use quite advanced materials to achieve their goals.
However, there are still a few designers out there using mainly plywood/epoxy like
Bernd Kohler, Peter Snell, some of Mike Wallers or Angelo Lavarnos designs or Alain Berthet for which I have never seen references in a forum but I like the design despite the Web Page (http://www.abmarine.fr/cariboost1/crbst_0.html).
All claim that plywood allows for strong, light and yet inexpensive designs. However, little can be found about customers experience with ply-catamarans.
Do some forum members have first hand experience here?