Ok, so here we go, I did some tests:

Sony USB2 stick on USB2:



Kingston USB3 stick on USB2:



Kingston USB3 stick on USB3:



SATA II disk on USB2:



Same SATA II disk on USB3:



You can clearly see that there is a difference, meaning an increase of speed, when using USB3.

However I also tested with the IO Level Up set to USB3, but there was no difference as to leave it disabled.