I cannot recommend enough that anyone who has run a Disney race in Orlando also runs one in Anaheim, especially in the same calendar year if feasible. If it's even possible, do what you need to do to have the experience.
1. It's interesting to compare what the strengths of a race on each coast. What any
Disneyland race lacks in theme park miles, it makes up for in community support be it cheerleaders, marching bands, local community groups (I've seen Hawaiian dancers, Latin American dancers, classic car groups with their classic cars), and in the case of Star Wars and Superheroes, cosplayers. In the case of Star Wars, the cosplay groups line the streets around miles 8 and 9 and offer incredibly detailed costumes that rival what the in park characters have. Having not ran Superheroes, I won't comment on those. I do know they are there. Also, if you choose Disneyland or Superheroes, the chance to run through Angels Stadium is incredibly thrilling.
2. The Coast to Coast. When I did it in 2012, I met some runners at both Disneyland and WDW who were not even aware of races on the other coast. This can also give a runner the opportunity to experience the "other" coast at a unique time. Running Wine & Dine or Superheroes means Christmas decorations in the parks.
3. (If applicable) Specialty medal for either the Kessel Run or the pink coast to coast for Princess & Tinker Bell. Obviously, this requires selecting companion races, but it's another unique medal opportunity. I won't be surprised if we see some sort of new challenge arise tied to this kind of idea. (Marathon weekend-Light Side or Wine & Dine-Superheroes for instance).