In terms of weight, they average about 3kg, the bigger bags a bit more. The babys super light. They are on the heavier side comparing to Osprey, or First Accent, but competed with the Carrimore backpack range. The bags were made from Cordura ripstop waterproof fabric, and are extremely strong. Yet to find someone that said a backpacker ripped or came lose.
Here is a great overview on this forum: