I have the Yosh EMS. I purchased this instead of the PCIIIr because I was able to get a great deal.
The Yosh uses almost the same interface as the Power Commander, in fact the maps are interchangeable. You can copy and paste a map between the two. Performance wise the two are identical.
The Yosh has a few more gizmos than the PCIIIr. It allows for expansion. You can add things like a shift light and clutchless shifter (of which I have neither).
Save some money and buy the PCIIIr. Unless of course you have a racer buddy who isn't running Suzuki anymore and wants to get rid of his Yoshimura EMS.