In reply to Beth-Cath-T:
Other half has a small POD cragsack in the small size - it was the only pack that we could find that fitted her.
I've got a size 2 cragsack and an Osprey Mutant - and whilst the Mutant is a bit lighter and arguably more comfortable when loaded (back on Cragsack is solid so it doens't matter how badly packed it is!) the Cragsack is far more robust.
The lid pocket is also much better on the POD.
I've also found that the cragsack sits better on my back when only partially loaded than the Mutant does and that the Mutant is a bit of a pain to shove stuff in - both due the the felxible back deforming lots.
I guess I could investigate a stiffer back sheet for the Mutant, which would help loads.
HTH
Si