I can see where you're coming from Wouter, but the Inter never came with an F18 spinnaker, so I can see where Devon is coming from also.
The Inter/F17 class in Australia is becoming a Nacra development class, they do change them alot here, now they are going to fit wings onto them.
To the best of my knowledge, Devon is the only one racing an Inter17 in Australia, but Nacra Australia has sold 3 X F17s recently so the class is growing. We will all know soon enough the answer to the equation.
F17>/<F16.