Category C (Class 2) LGV / HGV training runs around Ipswich, Suffolk and uses the DVSA Test Centre in Ipswich. C is the category that allows you to drive a rigid vehicle over 3,500kg.
USB 2.0 is much faster than the DVD data rate. DVD 1x (slowest) write speed is 1.39MB/s. DVD 24x (fastest) write speed is 33.24MB/s. USB 2.0 write speed is up to 35MB/s. A 24x DVD max is about 32MB/s while USB2 max is about 60MB/s.
When comparing 2.0 and 3.0 there are a few major differences. First the transfer rates: USB 2.0 offers transfer rates of 480 Mbps and USB 3.0 offers transfer rates of 4.8 Gbps - that's 10 times faster. Note that the transfer speeds also depend on the device in use in addition to the bus type and USB ports and cables.