I'm planning on buying an unlocked Samsung Galaxy S3 (Quad-core) and was wondering if there was any difference in data speed between the AT&T sim card and the Unlocked sim card because the only way you can get the AT&T sim card is if you have a AT&T GS3 (Dual-core) which has 4G LTE capabilities in which the unlocked GS3 does not. Will these two differences in data network affect the overall data speed of ST? If so by how much? Or is it just the same no matter if the phone has LTE or not? Any help would be greatly appreciated, thanks!