I want to try out an international version of an HTC One X on AT&T and I have the US version of the SGS3 with it's 4G LTE micro SIM card. Does anyone know if the 4G SIM card will work in the 3G One X or would I have to get a 3G SIM card from AT&T to try it out? Enquiring minds want to know! Thanks in advance!

Well, one way to find out so I'll see what happens when I check it out today. Thanks for your answer mac!