The battle between the Iphone and Galaxy will never end and will continue as both will be lauching their flagship devices.
Technology : in terms of technology the galaxy wins because it has developed high end technology of the curved glass depicted in the galxy edge series whereas the Iphone had not yet given curved display to its device.
Cost : Everybody knows to have a iPhone you need to empty your warm pockets. The galaxy will thus cost you less than an iphone.
Features : For this both the galaxy and iphone have been balanced points as they both have provided various features like in iphone the Siri, 3D touch, fingerprint, etc
As well as in similar way the galaxy series has high end hd camera, bezel less 3D touch screen and many more.
There are various points to be compared but my advice will be having a galxay one.