USB1 puts 1.2 or 12 MegaBits/sec on the wire, shared between transmit and receive, and between all clients of the root hub.. roughly 1 megabyte/sec in 1 direction if very little else is happening.
USB2 puts 480 Megabits/sec on the wire, or, if and only if it was running in one direction with NOTHING else happening, around 50 megabytes/sec.
BUT, as soon as other things happen, the available bandwidth for most usage does drop off considerably.
Then you have to consider what your USB2 peripheral can actually achieve.. some will be able to fill the wire well, but many will not, especially in the case of flash storage pens.. and writing data.
You also have to consider the underlying machine capability.
Iyonix hardware has the bandwidth to cope with all that USB2 hardware can throw at it.. however, there is a large amount of software involved in the usb stack which will set a limit on the absolute maximum real life speed that can be realised. Exactly the same set of issues can be seen with networking, and can be similarly seen on other non ARM platforms.
So in summary: USB2 is faster.. in the same way as it is faster on other platforms, but please do consider the sums before expecting headline figures.