Hope I get time for a more detailed write-up later but after months of planning on this forum, I've been out on several weekends of hikes now with my new lightweight gear.
Some positive, some negative experiences.
This last weekend, I did 35 miles in 2 days along the AT near the Delaware Water Gap in NJ.. 12 miles + 23 miles (12 mostly because I got to the trailhead late). Not much elevation change (~2400 - 3000 ft?) but really rocky trail.
Prior to this, I don't think I've ever done more than 10 - 12 miles in a day and that was a day hike with no pack! And now I hit 23 miles and wasn't exactly dead at the end.. was still cheery and only a little sore.
Aarn pack: I have the new Mountain Magic 55 and a lot of credit goes to it. I had 25 lbs in it to train for my Colorado Trail thru' hike. I experienced the mildest of discomfort in one shoulder at the end of the 35 miles but it was gone 30 mins after the hike.. it could even be from my very strenuous use and loading of my trekking poles to help my weak knees.
Besides the back comfort, I think this pack really does help posture. I only weigh 140 lbs or so and 25 lbs in any pack would give me somewhat bad posture, certainly after 25 miles, when I'm too tired to hold myself straight.
Trail shoes -- North Face Prophecy (similar to Hedgehog but without Gore-Tex). Weighs 1 lb 10 oz for the pair.
I used to use Vasque Breeze boots.. 2 lbs 10 oz or something. But these new shoes + superfeet were amazing. It was a VERY rocky trail and despite that, I was thankful in having less weight on my feet..
I was more nimble. This is important when I am tired because then I just start throwing my feet around on the trail, not caring where or how they land.. less energy to position the heavy boots.
With these light shoes, even at after 22 miles in a day, I was still placing my feet properly. It was also a very hot weekend and I was glad to have these small breathable shoes on.
I'll still quite amazed that I just about doubled my previous hiking distance. And I've already forgotten how tired I was at the end of this day while I remember the epic beaten-up feeling from some previous hikes when my whole body hurt and I felt near death in terms of exhaustion.