I am really enjoying this bag. My dog Ginger took to it pretty easily, and the two of us have only become more proficient at using it over the past week or so. She is 35lbs, and the load up was the most difficult to learn. I do a hybrid between the 1 person on the ground and 1 person standing methods. Once on my back, the bag distributes the weight very well. We commute on the Subway, and she has no issue being in it 30-40mins at a time. Ginger is in between sizes, and I ended up buying the booster block which greatly improved both my and Ginger's experience. Customer service is great too! Thanks for this awesome product.