This is my second pair of Capezio Rockits.  They are great!  I take 2-3 Zumba classes a week, and these are the best shoes I've found to allow for the types of movements done in Zumba (e.g., pivots and movements on the balls of your feet.)  It has enough grip for movement, but enough non- stick in the sole to avoid tweaking your knees.  I would highly recommend the shoes for hardwood floor/gym surfaces.