Anderton
Don't be too quick to write off that 3.0 port with an audio interface. I have an interface that was a little squirrely with USB 2.0. I plugged into into the USB 3.0 port to see what would happen, and the performance improved dramatically.

Same Here as the ONLY USB 2.0 port on my not particularly "audio optimised" laptop,was an e-SATA combo port,so was continuously losing the connection,would you believe,FROM it almost "Falling Out" it was so loose,only after updating the USB 3 ports[this lappy was an early "3" adopter],much better[though it was just the snug fit!],not actual performance LOL
Bob