The view of the fireworks from behind the castle is actually much better for the fireworks themselves. You feel like you are smack dab in the middle of them (because you are, they go off 360° around you back there).
While this is true, I felt like I was watching a tennis match. This got annoying very fast. You also don't see tinkerbell fly. But there's also hardly anyone there, especially if watching in New Fantasyland. Although, despite this, there will still be that one person who somehow decides that now would be a good time to watch and stand right in front of you. My guy actually set up his tripod, which, now that I think about it, why was he prepared to bring such a thing, but not prepared enough to set up before the show? This was like a few minutes into it.