Here is a very unbiased opinion on these two devices. it favors iphone 5 in speed. but color richness and display favors Galaxy S3.
I am very much a visual person, like beautiful things and beautiful women. so i favor Galaxy S 3 overall.
Babolat Pure drive 2012, 55 lbs, Kirschbaum Proline X / X-1 biphase. Nalbandian backhand and Nadal forehand.