In reply to r0b:
Mr TC has just got the Montane Jaws, and is very impressed with it so far. The bottles are more rigid, like 'normal' drinks bottles, than the squishy Salomon ones, which offers the benefit of easy filling from streams. He was a bit suspicious of how the bottles attached at first, but said it's surprisingly effective.
He tried on the Salomon and Inov8 equivalents, and found both seemed like they'd chafe round the underarms - for context, he's 6'3, skinny, but with broad shoulders and some lingering lats from years of swimming, but he couldn't be described as bulky!