Could not be happier. Leroy loves his pack, he turns into a puppy when we get his gear out because he knows he's going on a adventure. He turns into a little diva when his picture is taken.
The booster was exactly what we needed for our dog was right in the middle of the pack sizes.
The booster allowed our dog to have his front shoulders out through the shoulder holes better. In addition, it allowed him to sit up higher and look left and right of my head.
We have a Cavalier King Charles and found the small backpack was a little too large. We purchased a cushion and now he fits perfectly in the Backpack.
My sport sack is a size large, my dog fits perfectly in it when we ride bike. However, if we go for a walk she would sit a little too low. The booster block fixes that problem. If your dog, like mine, is in between sizes or just doesn’t sit quite right in the sack I would look into the booster. It’s definitely worth it.