From the Disney Blog:
...This new race, scheduled for Sept. 29, will follow a similar course through the set of Lights, Motors, Action! Extreme Stunt Show and past Mickeys Sorcerers Hat but features runDisneys first-ever 10-mile distance that finishes, appropriately enough, near The Twilight Zone Tower of Terror attraction. If you survive the experience, youll be treated to a shiny new medal and a rocking post-race party with your family and friends that features live music, Disney characters and exclusive access to attractions such as Rock n Roller Coaster Starring Aerosmith, Star Tours, Toy Story Mania! and, of course, The Twilight Zone Tower of Terror.
My opinion: Staying onsite, taking advantage of disney transportation to and from the race, huge benefit.