The document compares the storage capacities and speeds of the Samsung Galaxy S4, Galaxy S3, and iPhone 5. While the Galaxy S4 and iPhone 5 both offer a 128GB storage option, the S4's NAND flash memory provides read speeds of 140Mb/s compared to only 50Mb/s for the iPhone 5. Larger storage is currently only available for Android and Windows Phone devices, not the iPhone, as Apple does not offer a 128GB model.