Kitty Pryde going giant size, thanks to Pym Particles, and fighting Galactus.
The amount of effort the heroes put in stopping Galactus is awesome in itself.
The fact that it took so much more effort shows just how much more powerful the heroes of 616 Marvel are than the Ultimate versions.
It is more that the Ultimate U have never seen or even dealt with something like Galactus before. In context, you have a Reed Richards who is genocidal war criminal who knew what is what, but had to gather his alternate universe's information on him. Plus, this Galactus was amped by his own Ultimate counterpart's fusion, Gah Lak Tus. I