From our experiments with competing with various stick matchups we have found that single stick 28-21length tends to be boring for the uninitiated and mostly enjoyed by the people who know what they are watching. For people new to viewing stick fighting the two short batons seems to be the most pleasing visual spectacle. Single stick bouts are—I think—the greatest fighter test, but end quickly or proceed slowly. Double stick with the longs ends up with one fighter down to a single stick pretty quickly.
The two shorts or a short and long double stick fight seems to have a high activity rate and longer duration with more core contact.
The video below is slow, half speed sparring, for the viewer to be able to examine technique and stroke chaining and for the fighter to be able to consider same and adapt in slow motion before amping up the tempo.