I have the iPhone 5 and the Samsung Galaxy S4 (not the newer S5). The iPhone is an amazing device, but the Samsung is simply better.
For me, the ‘whole package’ of the iPhone is better. There might be faster CPU speed on a particular Samsung, more pixels on the camera, a better screen etc. etc., but the ‘whole’ doesn't stick together functionally any where near as smoothly as an iPhone.
IMHO.