Presumably (and this is a guess) it's an updated / relabelled version of what was on the 'old' WB-100. They offer more tonal variation - in the old world, the 'Pop' and 'Funk' settings were a little cleaner, whereas 'Rock' was full-fat saturation. I used Rock and Pop - they were quite handy to switch between for quick tonal changes. Funk was a little clean for me.