When I did Whitney overnight my pack weighed in at 43lbs at the scale with 4L of water(Laugh I know) but I also was able to drink when I wanted to and just sip out of the hydration pack.
My Uncle who did not have his camelbac filled when he started and only had his water bottle drank significantly less because it was inconvenient to grab the bottle.
I like the convenience of being able to just sip away when I am thirsty and not have to worry about reaching for my water bottle.
ultimately it is personal preference however.
