I bought the F1 Mainframe and 2 Batwing pouches to build a lightweight system for an upcoming trip out west. I am amazed with how light the set up is when it's all put together. For now, I've been loading it up with a 30# sandbag and doing step-ups and some short hikes (adding weight and distance through the spring and summer). The pack was easy to set up and adjust to my body type. I'm looking forward to putting it through its paces this summer and putting it to work this fall. Great quality from Eberlestock; buy through Guidefitter with confidence!