I carried a 21lb backpack + 4 litres of water up the summit to camp (28lbs altogether?)and to be honest, I did not notice the extra water weight after about the first three switchbacks. Even if I was not camping on the summit, I still would have taken my pack with me. Not only am I the non-trusting type, but I have a fair amount of paranoia that makes me not want to be parted with my gear.

My pack is an Osprey Talon.

The body betrays and the weather conspires, hopefully, not on the same day.