I have an Eagle Industries load out bag that has traveled in and out of the back of my pick up truck around the country for approx. 5+ years with nothing wrong but some dirt and scuffs. The first link below is to the 3-day pack (which I do not have) and the second link is to the load out bag that is made by Eagle that I have beat for 5 years.
I have nothing but good things to say about my Eagle bag - 'cept it can get heavy. But, it is near bomb proof. I suspect that the 3-day pack would be as well built.
http://www.eagleindustries.com/produ...tail.aspx?id=5
http://www.eagleindustries.com/produ...ail.aspx?id=11