Overall I was quite pleased, the biggest change I would make it to make the chest straps stronger. Once you get them tight they tend to stretch out and lose their place.
I've used this pack a few times for hiking after my last pack finally fell apart. It's extremely comfortable, holds everything I need to carry, and is very lightweight. I haven't used it for trail running yet, but I know it will work well for mountain biking and keep me cooler due to how its padding provides excellent airflow.