The keys are "make it cheap" and "make it easy". Easy to build (if homebuilding is to be a serious option), easy to transport, easy to rig and easy to sail. The Opti used to be like this, but no more (50 measurement points when measuring a hull?).
The potential for a kid having fun (with friends) is much larger on a cat than on a Opti. A cat is the perfect platform for bathing and other fun water activities. If the boats are fast in addition they are fun.
In the end, it's the parents who has the money or the resources to build a boat. Cost is a deciding factor not to be underestimated. Another factor to consider is how to get it started?


Wouter: I have buildt a Quattro16, which is a Pixie scaled up a bit. Simple to build, but all those full bulkheads add weight.
Do you have any pictures of the traveller setup you described?