I wanted to like this bag. I was planning to use it like how it should be used...for a 4-mile bicycle commute to work everyday. The bag is well-made with nice features, but there were two things that made me decided to return it:
1. Main point: this was the first messenger bag I've tried, as I've been using a backpack up to now. It's not for me; too uncomfortable. The same load from the backpack (4.5-lb laptop, charger, water bottle, small bike repair kit, light rain jacket) felt much heavier when hung from a single strap. It was cooler (temperature-wise, not as in hipster cred) on my back than a backpack, but that wasn't worth the penalty in comfort.
2. Secondary point: although the material of the flap that closes over the bag seems waterproof, the vertical sides of the bag can stick out from underneath the flap. Thus, rain could conceivably get into the bag. As this was one of the main reasons I bought the bag, I decided it had to go. At least the Amazon return went seamlessly.