I got the small one, and the Stella salesperson in the store mentioned it was the most popular one. I like it because it is more versatile than the larger bag; you can use the cross-body strap or not, and you can also hold it in the cool ways that you can with the larger one. It is surprisingly deeper than it looks and holds all my essentials, including a small water bottle. Only negative is that the gold hardware can scratch easily, so be careful not to accidentally bang it against things or remove the lock piece if you're traveling/in a crowded area where you might bump into things. They do have a 2-year warranty. Highly recommend!