My dogs (mini doxies) don't like this toy at all. They hate putting stuff in their mouth, so they try to always pick things up with just their front teeth (even balls). I found they wouldn't play with it alone at all, they would quickly get bored and ignore it. Pushing it around didn't dispense anything like the roly poly kind we already have. I had to hold the toy and my male dog would yank on the very end of the rope and sometimes a treat would fall out, but i had to "reset" the rope each time. They just don't want to pull very hard or grip with their whole mouth.
Disappointing really, but then again, their favorite "treat dispenser" is the leg of a pair of jeans cut off and tied into a knot, with the treat inside. Believe it or not, they actually untie the knot, rather than rip holes in it. It used to take them about 20 mins per leg, but now my female dog does it in about 3 mins.... My male dog likes to chew on a skein of really cheap acrylic yarn, so really, what more could you ask for?
Video of the dogs untying the knots: https://www.youtube.com/watch?v=_agMdNJsDuE