Yes, large part of the Samsung is made from plastic, but it's different kind of plastic. At least on my Galaxy S2, the back cover of the GS2 is very thin, but very strong and flexible. It can be bent less 90 degree without any problem. So, plastic is very different. It's just like steel, high end steel could be 10-20 times stronger than low-end cheap steel. I think GS3 should use the same quality plastic.