No, the difference isn't that much unless someone is trying to justify their purchase in their head. "Faster camera is totally worth it". WhoTF are you, paparazzi?
To be honest, right now, the difference is nominal. Maybe when iOS 6 and heavy A5 optimized games release, then you'll be able to tell the difference in speed. But unless you want a new camera or Siri, the upgrade isn't worth it.