[pct-l] thru backpack size

[Brian Nyquist]

i would like to have as many opinions as possible concerning the  most
appropriate size/type of backpack for a thru hike of the pct.

i plan on packing med-light but feel that a pack which could potentially
carry 40-50  lbs for multiple days important.

i have been seriously considering the arc'teryx bora 50.  if i am mindful of
weight/volume constraints what are the pros and cons of my current choice?
-brian