I use this bag on my 7.5 mile run to work. It's been excellent for all my needs. I originally was going to buy the Dyna, which is the lighter running bag that Oprey offers. But this bag seemed more durable. And I'm already running with 10 pounds. The extra ounces of material doesn't matter at that point. My biggest compliant about the Sirrus 24 is the lack of places to to hook on a safety light. I've tried hooking lights to the side pockets which usually works but when you stick on the rain cover there is no place for a safety light and that is when I need it the most. Also the rain cover could be a bit more reflective. Other than that I love this bag. I'm a smaller person. After trying fifty other bags at the store, I found this bag to be the most comfortable and adjustable. I can tie it tight enough for a sung fit that I need while running. The frame keeps the load suspended and from bouncing around. 24 liters is perfect for all my needs--winter wool coat, office work clothes, dress shoes, make-up--etc, dry shampoo and lunch. And it doesn't look or feel like a clunky hiking bag, so I can still walk into the office with it.