Like BMatthews says, and build the model as big as you can, then the 'scale factor' starts to work for you. Just fly it like you are in it, and you don't want to lose your breakfast. Scale speed (and therefore performance) will always be a contencious issue, consider, for instance, that the whole performance envelope of a full size WW1 fighter will be done at an airspeed less than the landing speed of most WW2 fighters and you can begin to see the difficulties for models, and what effect any wind over the strip could have...
Evan.