We bought this rucksack recently for my son's first expedition for his bronze Duke of Edinburgh award. Although it was only for 2 nights, we chose this one because he is committed to doing the silver & gold which culminates in 2 weeks in Norway next year & so wanted something that would be sturdy, not too heavy, & functional. It ticks all the boxes as it expands to allow you an extra 10L storage plus it has a very useful central access point so that you don't have to take everything out of the bag from the top to get to somrthing near the bottom of the bag. The TFX back system means that it fully adjusts to the height of the wearer, & in my son's case, will have to be adjusted a few times before he gets to Norway next year at the rate he's growing! He found it very comfortable once it was full of equipment as all the weight was taken on his hips.
A great buy.