Apparently they now call it "Tragna-maction" instead of "Ultimate Grip". I had the Great Beauties board from last year. There aren't serrations like Mervin's Magnetraction, but a few different length and radius edges along each side. This is similar to Never Summer's "Vario Grip" and Salomon's "Equalizer' sidecuts. I believe there are subtle differences between these, but the principle is the same.
I didn't see any tech description on Yes's website, so no help there. Go to NS's website and look into their Vario Grip as an indicator.