I went through a mock bugout where I not only carried my INCH but heavy BOB, vest, harness, extra weapons, bags, gear, water and clothing. And ran/jogged/ran jogged five miles on a dirt road for five miles, just to see if I could do it. (Full details will be on my site. It actually hurt, but I know I could do it if I had to (and the nieghbors would leave me alone) irl... I just lay there in the ditch still wearing my gear and gulping powerade and letting my body tell make that I was too old for such foolishness. I walked home and spent some time in the hottub with my old friends Aleve and and a muscle relaxant and saying never again. I plan the next one soon.
Snake offers us a golden tip here: don't just pack a bag and be done with it. Get out there and get dirt time with it. Carry it and use it. Put your kit and yourself through the paces. Everyone is going to have their own comfort zone in terms of gear and weight, and the only way to truly find yours, IMO, is to get out there and test out your setup.
Personally, I get out with my kit as often as I can, day hiking or overnighting, and make adjustments every time I get back. It's all well and good to get feedback from like minded folks (and I, for one, really appreciate the insight) but ultimately, you're the one who's going to have to carry and depend on your kit. That sweet spot where theory and real world experience meet is where you want to focus.