As a former hs band member I would say marching band was more fun because it was easier. But as a current band director and educator, I would say concert season is better for far too many reasons to list.
It seems ridiculous to me to spend nearly six months on three pieces of music. What if all you did in English class was read and rehearse the same 3 poems every day in class? As an English teacher, you wouldn't be employed very long.
Music is not a sport. It is not a competition. It is an art form. When we focus on "we're not as good as they are," then we miss the point. My fellow directors and I should be more concerned with the individual development of each player. The focus should be "are we better now than when we started?" This is why I prefer concert season. Concert season gives us festival, which is a band being measured against a set of set criteria, and not against others bands. (Yes, I know that marching competition also has criteria. But it adds the element of finishing ahead of someone else.) In addition, I get to see my family more during concert season.
Don't get me wrong, I love a good marching band. But I presonally prefer concert season.
The Doctor of Musical Mayhem