My first smart phone was an iPhone IMHO, JMHO once you'vce used one of these you are forever spoiled.:W
If you have an iPhone and even thinking of switching to Galaxy I would highly suggest you use someones Galaxy BEFORE you switch. I did and there is so much junk on each screen.
I found it real hard to read and the screen touch is nothing like the iphone. Breathe on it and its switching screens and sending you all over. I just picked up a second phone that is an android. Boy that is even worse.
IMHO once you've used the iPhone everything else is less, they have the touch screen down to a user friendly science. Apps are easier to use, etc. I also found the Galaxy awkward to hold because of its size compared to the slimmer iPhone.
So I most likely will not buy the new bigger iPhone for the same reason.
Just saying, It's what I found to be the difference and why "I" would not buy a Galaxy. Just my