Chipworks posted some polysilicon die photos that compare Apple's A4, A5 and A5X processor. What's most striking to the casual observer is the relative size of each die. As Chipworks notes, the A5X is "big and beautiful" when compared to the A4 and even its close predecessor the A5.
You can see the detailed photos with block annotations on Chipworks's website. You can even grab a high-resolution version of the A5X that you can use as a desktop wallpaper.