I'm looking to buy a new external hard drive to run Time Machine. I currently own 3 EHD's (from 750GB to 2TB) but they are all USB 2.0 and SO incredibly slow to transfer files. Sometimes it literally takes 6-7 hours to copy 100 GB to and from the drives...drives me crazy. And it will really drive me crazy once I enable Time Machine. So I am wanting to get a newer 3TB EHD with either Firewire800, USB 3.0 or Thunderbolt but am having trouble deciding what to get. Currently I have a 27" mid 2011 iMac (2TB) which has Thunderbolt and FireWire800 ports but no USB 3.0 port. I will probably be upgrading my iMac within a year or so and I've noticed the newer models have no FireWire800 port (which I need to take into consideration when choosing an EHD). Some of the EHD's I've looked at (WD, LaCie, OWC, etc) have 2 of FireWire800/USB3.0/Thunderbolt connectivity but not all 3. That is making it difficult for me since I will probably upgrade in the next year or so. What do you recommend? Which is the fastest of the 3 (FireWire800, USB 3.0, Thunderbolt)? Any particular brands/models that work best?