I just bought an Imac 5K with a 2tb Fusion Drive and am looking for additional storage for fast access and backups. I am considering a G-Technology or LaCie thunderbolt drive and am looking for opinions as to what everybody else is using. I also was wondering if USB 3.0 is just as fast considering the 7200rpm drive bottlneck. I am trying to find the best cost effective options. Thanks in advance.