Galaxy S3 or Nexus 4

Hi All,

So I have just received a brand new Galaxy S3 and not yet taken it out of the box and with the Nexus 4 going on sale next week I am tempted to stick the S3 on Ebay and buy the Nexus 4.

In my mind the bad points of the Nexus 4 is the limited memory as I like to have my music library on my handset. However I think having stock Android is enough of an advantage to overlook this.

What I am more worried about is the camera quality and battery life. Has anyone done a good comparison of these and the S3 equivalents?

I like the idea of having a good camera on my phone and want a battery that will last the day...