I have a GS3 and an iPhone 5 and I did a side by side panorama shot and I can say I was surprised at just how much better the iPhone was.
The GS3 had lots of blurriness and artifacting while the iPhone 5 looked sharp and crisp. Much much better.
Just for the record I think there can be little doubt that the GS3 is a better phone than the iPhone 5, with the exception of build quality where it doesn't come close. This is me being objective. I still find myself loving the iPhone 5 despite not having a lightening cable and having to borrow one to charge my phone and a small chip.