I have a GR2 and I love it! As for tough, I highly doubt you'll find a tougher backpack. I've carried absurd amounts of weight in it and while wearing and it still stands up. I've done a GORUCK Light and a Challenge and yes they do build better Americans. All I can tell you is that if you buy one, you'll never have to buy another bag because they're damn near unbreakable. Worth every dime!
Interesting article about the police and fire partnership in different scenarios with some things that are up and coming for both services. Also, there is another link posted as well that offers some truly interesting insight.