This is the most perfect bag in the world. I bought it on a whim one day and don't regret it. I bought the small because it was just the right size to carry around yet small enough to also toss into my canvas bag when I need more space. (I carry a LOT of stuff some days.)
I'm about to move overseas and I'm going to purchase the medium sized one for a bit more room. As it stands though if you're looking for a compact size that offers enough room for things you carry in your day to day this is the perfect choice!