Well if you ever plan on upgrading your motherboard/getting a SATA III expansion card, go with SATA 3, otherwise just stick with SATA 2 to save money. Or if the difference does not matter to you, it's safer to go with SATA III. I just recently got an other SATA II 120gb SSD because I knew I was not upgrading motherboards any time soon and I didn't want to spend the extra $$$ when I wasn't going to be using it to its full capabilities.