Let me call my response to this thread
A Tale of Two Hikes.
I was in Alaska again in September, and participated in two longish hikes while I was there. The first hike started at sea level and climbed to the top of Sadie Knob, across the Ketchemak Bay from Homer (I was staying on the other side of the knob on Sadie Cove, which really should be called Sadie Fjord). Elevation gain was about 3000 feet. The bottom half of the hike was in very tall brush that was soaking wet, and that made us soaking wet. Everything got sunny and dried off when we got over the tree line (which is only at about 2200 feet above sea level in those latitudes). Distance was a little over nine miles for the whole hike, with lots of required careful foot placement due to rocks and roots hiding under the brush. (At least the bear that had left very fresh prints and scat on the trail didn't bother us).
For that hike, I took the 645z with the 55 attached to it, mostly because I was unsure of the wetness conditions and wanted something water-resistant. That was correct thinking, even though my 28-45 is also weather-resistant--I just didn't want to carry that much weight. (I was hiking with the daughter of our friends and a couple of her friends, who were worried I wouldn't be able to keep up. Ha!) I took that plus a water bottle, a sandwich, and a hiking stick that doubles as a (too light) monopod. I found (again) that the camera hanging on a neck strap becomes a problem, not because of the weight, but because of the swinging. I ended up carrying the camera in my hands, and because of the wetness and tall brush, I had to hold the camera at shoulder height for much of the hike. Switching back and forth between arms managed elbow soreness. No real complaint but it was not optimal. My inadequate lightweight hiking shoes were attacking a couple of toenails and that had my attention far more than the weight of the camera.
Sure, there were times I wished for both a shorter and a longer lens during that hike, but you make the photos that the lens you have in your hands will make.
Later that week, I hiked to Crow Pass from the Girdwood end of the Crow Pass trail--about 7.5 miles round trip and maybe 2500 feet of elevation gain. This trail is part of the historical Iditarod route that is near Anchorage. This time, I wore my camera daypack--a Think-tank Streetwalker--but took out most of the camera stuff and put in water and lunch. I brought the 28-45 (!), the 55, and the 200. For that hike, I hung the camera the way I should have done going to Sadie Knob. My strap has steel clips that connect 8" pig-tails to the neck strap--those pig-tails connect to the strap eyelets on the camera. When wearing that pack, I remove the neck strap and attach those clips to D-rings on the shoulder straps of the pack. With that rig, the camera is high enough not to swing and the weight is not on the back of my neck. I never noticed the weight of what I was carrying (but I am reasonably fit). I never felt like I didn't have the lens I needed during that hike. I was wearing my good mid-weight day-hike boots that day and my feet were thanking me.
During my last trip to Alaska, I hiked from Kennecott to the Root Glacier and back--a fairly flat 5-miles round trip--and carried very light daypack (with lunch) plus a waist pack with my lens choices--35, 45-85, and 200. To my waist-belt, I added the lens case for my 400 and put a water bottle in it. That trip was during an extended weight-loss period (I had lost 50 of the 80 pounds down that I am now), with only moderate fitness. Since then, I'm post-cancer and my fitness, while not where it was during my endurance sports days, is reasonable for an old guy. That probably contributes more to enjoying day hikes with a big camera than anything.
With the 200:
With the 35:
My wife made this photo on her Nikon:
There have been many more hikes, and I think the only repeating pattern is 1.) hanging the camera from the pack's shoulder straps when possible, and 2.) always bring the 200/4, which is too tiny to leave at home.
Rick "still working on the images from the recent trip" Denney