To be honest, I am not a fan of how similar it looks to the S3.
However I will try and play on one in person and see what it is like (sisters husband is ordering 1) but then again the specs change per country which is a downfall.
I would suggest looking into some of the specifications that are important to you. The Nexus 4 has a stronger battery life so if that is something you find important, stick with the Nexus 4.
Been there done that. I loved the speed, look and feel of my stock N4 but the erratic signal/reception i was experiencing made the phone unreliable. I went with a S3. Yeah its slower but its stable and reliable. Love my N7.