Blimey - I see I upset a few fStop fans

I agree that for a rucksack purpose designed for carrying camera gear I've seen nothing better - actually I've seen nothing anywhere near as good...
Happy now ?
However....
A quick Google to illustrate what I meant turned up
this feature list.
The section on Back Systems succinctly states.
Adjustable back system :
Usually on larger backpacks, they allow the distance between the shoulder straps and hip belt to be increased/ decreased to suit people of different heights, providing a more comfortable fit.
Most manufacturers now have slightly different types of adjustable back systems. The general principal in them is the same which is to allow the shoulder straps to be moved up or down to accommodate longer of shorter backs.
Air flow back system
Some rucksack have a tensioned mesh back that creates a large air space between the bag and the users back, keeping it cool and free of perspiration.
I sure you will all be good enough to correct me, but the fStop rucksacks I've looked at don't have either of those.
The fStop type of back system is frequently seen on smaller rucksacks. It's fine for light loads all day or heavy loads for a part day, but is still not as comfortable as proper expedition type back system.
On my expedition rucksack I can vary the back length without taking the pack off; I use this to relieve pressure points on my shoulder and hips at the end of a long day.
My rucksack is slightly unusual in that it doesn't actually touch my back except at the hip and top of the shoulders. This means great ventilation and my clothing moves freely meaning less effort reaching when scrambling or using trekking poles.
Quoting my earlier post.......
You need a proper adjustable and ventilated back system.
You only get those by buying a proper hiking rucksack.