I currently am using the the 5S and prior to this I had the iPhone 5, 4S, 4, 3GS, 3G.
During my spell with the 4S and 5, I also tried the following for a maximum of 2 weeks each: HTC Rezound, Galaxy S3, Galaxy S4, Galaxy Note 2 and Galaxy Note 3. The draw that keeps taking me to android devices certainly is not android as an operating system. I much prefere ios and its app store too. I am in the camp that longs for a larger screen. I find the screen on the Note series to be too big for me however.
Also, even though you will find tech blog after tech blog saying that the 1136 x 640 retina display is 'outdated' when compared to the 1080p screens of the S4 and Note 3 type devices....when side by side I find the clarity, crispness, and sharpness to be much better on the iphone....let alone the more accurate colors of the LCD display and brighness level of the screen.