I agree the OM about sleeping bags. I think if you have a good sleeping bag that has worked well, in the location that you backpack, then stick with it. For me, the sleeping bag is my last line of defense agianst hypothermia. A little "more" than needed is OK. Those temperature ratings assume you are well fed and healthy. A few times I have been less than well fed or had some kind of bug. Being able to set up a good shelter, hop in a good sleeping bag and lay low until weather or illness passes is a good safety measure. Same as OM, I have NEVER regretted my over-done bag (5-degreeF rating).

I have said this before, but water can be heaviest item you carry. Simply reducing the need to carry as much water will save a lot, and it is not that expensive. Do you really need a water filter? Some really do; others can get by with chemical treatment tabs. When I carry a filter of any kind, I pump water at water encountered, and thus, carry little between. When I use purification tablets, I consider these as just a means to reduce the risk, not eliminate it. I carry 1 L water maximum, and drink raw water from sources if that turns out to be insufficient. Not advocating this, since I seem to have an iron stomach and never have gotten sick from this; others may not do as well. A little more consideration of water, how much you carry and how you purify it may be useful. Do you use a hydration bladder? How much does that weigh? Is taking a pack off to get a drink of water really that much of a chore? Do you really need bombproof water bottles rather than used bottled water bottles.