Alright so in the world of FroYo in Arizona there is 28 stores on every corner. They are plentiful. On my corner, I have Yollipop and Kokomo.
Kokomo is my regular place. I've had their little punch cards and gone through a few to get my free yummy FroYo goodness. Let's just say that I'm a regular. With that said, Kokomo is a great place and they've set the bar pretty high for FroYo.
I think that Yollipop only beats them in one area - FroYo flavor selection. I think that Kokomo plays it safe and sticks with the standard flavors and rarely changes from those flavors while Yollipop is more adventerous with their flavors.
The part that really made me not like Yollipop as much was their fruit. It seemed old... and squishy. I want my fruit (about the only topping I get at FroYo) to be CRISP and fresh. My brother also felt the same (also a big fan of Kokomo).