Nexus 4 or Galaxy S3

So I've been researching both the N4 and the S3 and I've come to a stand-still. The Nexus 4 ($150 on Koodo) and the Galaxy S3 ($400 on Koodo) both offer me relatively similar specs and experiences. However, I've heard the camera on the S3 is better than on the N4, which is very important to me.

I want to replace P&S Cameras with my phone, can anyone help me to shed some light on the advantages/disadvantages? Is the S3 worth the extra money?