Martin you can't go wrong with WCW backpacks, I have had the V1 from them since July last year and it is still going strong. I wear it on my back as I find this the easiest way to carry it, I find the weight of the backpack is spread over your shoulders, back and legs. you wouldnt carry a concrete fence post down my your side, you would have it on your shoulder.
Just stated that before everyone starts saying its too heavy etc.
Matt