My experience is that the Osprey carry system suits me but I'm not so keen on the bag on its back (Exos 48L) but I'm not going to change it. My main gripe and I know its just a minor point, but I have never liked the rucksack colours, I have the black/gold version. Also the Osprey rucksack cover is just too flimsy, for such a costly item its just too easy to get small tears and holes in it.
I have a 50L Lightwave, sturdy, but for me it always made my shoulders sore.
I would have liked to have purchased a Nigor Zero but at £174 the price is ridiculous. I have a Golite Jam with a roll top, the Nigor is basically a Jam but with a proper lid.