Hi Andy,
In the short term my work will allow me to try it out in the UK on extended rambles and if it doesn't work for me I can have a back up arranged. I don't feel that short haul to a fixed camp location will be a problem (based on a load up today) even with the fixed back but over the next month or so I will be able to try both. Long-term ownership will probably see me doing more of the short haul stuff and it does have a good volume for shifting kit which was my original plan.
I do occasionally go out to North Africa but that wll not be for a while now so 'extreme' use will have to be the judgement of any potential buyer but i will try and help with what info I can give.
I'd love to compare it to my £20 50l TFG fishing rucksack (adjustable contact fabric padded back, aluminium bar frame, good padded waist belt (with pocket), fixed pockets, integrated rain cover, extra gear baffle, front entry, waterproof bottom etc.) - how heavy is it? The only downside to mine is the weight - but that's a hefty price for something that sounds in a similar league.