First of all, I'd like to be clear that this bag is very good quality. The fabric is thick and rain-resistant, and there is a mountain of padding in it so that you can put your laptop in there without a supplemental cover and have no worries. The stitching seems like it will hold for years to come and the design of the pockets is functional and generous.
What one may not be prepared for, however, is how big the bag truly is. All of the padding makes it full-sized even when it's not carrying any items. The bag is a very deep bag to begin with, and the padding just takes away any "deflating" that you could achieve by keeping the bag mostly empty. As for the material, it's durable, but it sort of feels like a raincoat because it's a little waxy. The strap had enough adjustment range for me, but the velcro worries me a little. If you're wearing a sweater and have your strap adjusted, the velcro will be exposed and will easily snag your clothes since there is no cover provided for the velcro.
The bag is definitely durable enough to handle heavy loads, I just wish it didn't look like it was carrying a heavy load when it's practically empty.