At "material", it is quite difficult to rebuke this smartphone: powerful processor, gorgeous OLED screen with accurate colors without any ghosting, powerful camera, good reception as wi-fi and 3G, 2GB of RAM for a more comfortable multitasking on iPhone ... Even the plastic finish is satisfactory. Samsung engineers have done a great job.
At the software level, against the catastrophe we frieze. Partly because of Samsung, which saw fit to fulfill the (very) thin 16Gb storage by a series of often unnecessary and not always désinstallables software! At the point that a good half of the capacity is monopolized before unpacking. And if you thought like me to run applications from an SD card, no luck: the applications must be installed on internal storage.
But above all, it is Android that frankly unsatisfactory. The Galaxy S4 may well be with a beast-processor runs, the OS fails to follow and games, even just greedy, lacking fluidity. One might argue me that this problem concerns only the players, but the game is pretty much the only reason to have a powerful processor. Another problem for Android Google Play (the "App Store" for Android). In terms of number of applications available on paper, Google has caught up on Apple. But on paper only. Quality applications are much rarer. This feels especially on games, but not only.
All this leads me to conclude that Android is undoubtedly an interesting system for low and medium-end devices. But this OS simply does not take advantage of the power of the S4. I'm much happier with my iPhone, even if the 5-inch S4 lacking a little for the comfort of surfing.