(Check our review of the Galaxy S3) The Galaxy S3 will go head to head with the iPhone 4S when it's released on 30 May, representing the biggest threat to Apple's hegemony. Both smartphones have similar suggested retail prices at £499 for the 16GB models, which also makes them the most expensive mainstream handsets on the market. Storage & Memory  The base 16GB models will probably do the most business, but the S3 can scale up to 128GB. The maximum...