I have had this phone for a year and a half, as of September 2015. Overall, I have had no problems whatsoever with the phone and it has always been super fast.
The phone is so easy to use that my 4 year old twin son and daughter can use and it also walks you through the phone and everything it has to offer.I really love the remote control that it offers cause I can access all of my televisions through out my house as well as my dvd and blue ray players and even our gaming systems in every room so I don't have to hunt down each and every romote control because I can use my phones remote for everyone one of my electronics.
I love this phone! The colors, the features and the capabilities are tremendous. Would love to see some firmware to make it a dual boot device, but other than that, completely satisfied with every Samsung product I've ever owned. :)