Ever wonder which wired connection would transfer your data the fastest? Well, connection ratings are theoretical maximums, so, for example, USB 3.0 looks like it should be 10 times as fast as USB 2.0 but in a lot of cases it may only be half that or less. And it’s important to remember that speed depends on what you're attaching to as well - a spinning hard drive may have very different results than a solid state drive.
But, if you want to keep your life simple, just remember that if you can do it with Thunderbolt then that's great but USB 3.0 is a solid option and, for now, is a lot more common, too. - Jeff MacArthur