We have two dogs: an elderly English Bulldog and an adolescent American Bully who both love this treat dispenser. It's definitely the best in our enrichment toy collection for its durability, how much kibble it can hold (~0.5 cup), ease to fill and clean, and versatility (since not all toys adapt well to our two dogs' very different play styles and mental needs). It also smells the best!
It's tough enough to withstand my young dog's gnawing yet gentle enough for my elderly dog's teeth. It's easy and rewarding enough to keep my elderly dog interested and playing without giving up before it's empty... yet still difficult and engaging enough to keep our young (and er, smarter dog) dog occupied for a while, too.