I'd argue a good roleplay wouldn't limit its audience to a word count minimum and be coordinated by a leader, not a compliant or retiring writer disengaged from their players. I'm always considered long-form ideal in constructing a traditional narrative with the added twist of it being composed by multiple writers, though my experience with live roleplaying is pretty much naught. But I'm attracted, perhaps to a naive extent, to the concept of the collaborative story. I will say it's hard to run a long-form roleplay correctly, however, due to a lot of misconceptions considering "literacy" (poor man's term for defining "writing well"). As I see it, a true game master that holds himself or himself responsible for the facets of their project rather than relying on and consequently blaming their players when things go sour is what is needed for an engaging experience.