From Personal experience I've owned the Galaxy S and the Galaxy S 2?
Needless to say I nearly gave up on the Bugginess of Galaxy S when Galaxy S 2 came out. I thought it had to be better. Yeah it was faster in operation and the speed at which it connected to the internet since it was 4G......
2 Months goes by and my camera stops working. All of the sudden I started getting Force Closures every time I tried to use my Camera. Then all of the sudden my Phone started rebooting and would not stop until you pulled the battery. Needless to say that phone is sitting in a Drawer...
One word of advice......... If you ever have a problem with your device and any carrier says you need to contact Samsung for support you might as well smash your self in the face with a hammer. Their support is the worst that I have ever delt with period. I knew when I had issues with my Samsung TV I should of just avoided them like the plague, but figured maybe it was just once. Needless to say I no longer have a Samsung anything in operation in my house anymore.