Up to now, this has been the only puzzle-type toy I've purchased for our Pit-Terrier. She's loves treats, but is also a very aggressive chewer. I needed something that was engaging, yet durable, and this fit the bill.
Our dog is very bright and figured out how to get the treats, fairly quickly. I'll usually go two or three sessions with her, in about 10 minutes. When she smells a treat but can't get a cover to move out of the way, that's when she can get frustrated and try to gnaw at it or swipe it much harder. When this occurs, she really doesn't want me to help. She'll nudge my hand out of the way, so I only move things when she absolutely can't.
The push-down squeaker, in the middle of the puzzle is a great thing to use to signal to your dog it's time to play this puzzle game.
Taking head from some reviews I had read, I watch our dog the entire time she's playing with this, because I can see how a paw nail could get stuck in some of the slots, if unsupervised. I also recommend cleaning the toy, after each use. Wiping the openings to remove any leftover slobber or treat crumbs is easy to do.
Note: Even though she's a medium-large size, I typically give my dog very small treats and I wanted a puzzle game that would accommodate that. If you are looking for one that can fit large treats, unless you break them into smaller pieces, this probably isn't for you.