The screens are about as bright as one another. The colors however are more vibrant, and vivid on the S3. The user experience however isn't particularly better on the N4 over the S3, but the lack of LTE is what made the difference for me.
I have both ATM, I totally agree with the above. We don't have LTE here so I am having real trouble deciding between the two, it would be nice to keep both but I can't afford it.