Interesting that they've gone to simultaneous shows. If I recall correctly, when it first debuted the fireworks were scheduled 30 minutes after Fantasmic, so they'd start about 5 minutes after Fantasmic ended.
I presume they ran into people either stampeding out of Fantasmic early to try and get to see the fireworks, or too many people leaving Fantasmic were trying to exit the park while the fireworks were going on. (I know they had that issue during Star Wars Weekend to try and keep the sidewalks along Hollywood Blvd to be walking only, no standing)
Then there were nights I saw the fireworks ran 15 minutes before Fantasmic, so that Fantasmic started just after the fireworks ended. Still doesn't allow viewing if both shows, but I guess they must've had a crowd flow problem with that, too.
I wonder how long they'll stick to this simultaneous schedule before they try a 4th schedule...
-Rob