I had an SII then upgraded to an S4. My wife has an SIII. As far as I am concerned, both Phones fulfill our needs. Cannot live without these devices. Relatives and some customers have iPhones. Even THEY agree that we have AWESOME smart phones. I have added 32GB memory cards to both phones. These things are justs like mini computers!
Whatever your need, there are hundreds of APPS that will satisfy. I don't work for Samsung but am a fan of their products!