USB 3.0 is fantastic. Not only does it run at 5Gbps—10 times faster than its predecessor, USB 2.0—but it also corrects a lot of performance issues as well. If you are dealing with content 16 GB or higher, you must consider USB 3.0 as a preferred choice.
Here is the key difference between USB 3.0 compared to USB 2.0
USB 2.0 offers transfer rates of 480 Mbps, and USB 3.0 offers transfer rates of 4.8 Gbps — 10 times faster.
USB 2.0 provides up to 500 mA whereas USB 3.0 provides up to 900 mA. The USB 3 devices provide more power when needed and conserve power when the device is connected but idling.
Instead of one-way communication, USB 3.0 uses two unidirectional data paths, one to receive data and the other to transmit while USB 2.0 can only handle only one direction of data at any time.