I love the everlasting fun ball. We don't use it for food anymore, but it's harder to work than the cube, but more fun to chew on.
I don't remember exactly how the buster cube is configured, but if there's a large size kibble of the same thing you feel, you could try that to make it a bit more challenging...larger pieces are more difficult on a lot of those toys.He still loves his Buster Cube, I'd just like to offer a different challenge. Maybe I'll keep it and buy one other treat dispensing toy and just start switching them up at dinnertime so that he has to adjust to their different styles.
I'm going to second the "Leo" our dogs love theirs. Stuff the lower part with kibble and the long part with peanut butter and they're set for the evening.Roxy likes the Leo http://www.caninegenius.com/
I jammed her antler in it once and surprisingly she really liked that- I think she had been having a hard time holding it up to gnaw on or something. Kibble and hot dog bits work great and keep her busy quite a while.
We have a tricky treat too. Say "kibble ball" around here and you will have a fast friend.
Wow, that one's pricey! I think I've seen something similar at Petco, but not too sure.the Dog Pyramid