I have both an iphone and a samsung, they both are good. You can have your preference for specific reasons. I say, if you have small hands, get the iphone 5, if you have big hands, test them both out. If you like productivity, get the iphone. If you like having open source, get the sg3. I haven't found anything spectacular about the sg3 since coming from an iphone 4. The bigger screen is nice, but its almost too big at times and I don't like how small the home and back button are on the sg3.
Just my take
2006 325i: Matte Black Grills, AG m310 19's (19X8.5et35 & 19X9.5et33 - 235/35/19 & 265/30/19), Amber Covers, Magnaflow with black tips, Blacked Emblems, M3 Replica Bumper and Vorsteiner hood!