Nuns mentioning of a cross country trip certainly made me think that with his RS setup and total bike/load weight, this will certainly make a real difference in days and days and days less traveling on such a long trip. For anyone, we tend to have a certain power output that we are comfortable putting out for all day, and especially day after day. Yes we get stronger over a trips duration, but for a given power output, pushing a 40lb bike/load combo is always going to be a bit faster than a 70lb bike/load combo, especially with all the ups we hit every day depending on the terrain. So it certainly makes sense to me that if you can cover lets say 25km more per day on a lighter bike expending the same amount of energy (a number I completely picked out of the blue), imagine how this will add up over many weeks--600km per month easy, and its not even meaning that you are pushing yourself more.
Could mean a cross country trip time could be easily a week or two less than on a bike with 40lbs of stuff, plus you save on accommodation, food costs.
Good points, I agree...
I did the ST on a similarly light weight setup to what I think nun plans to use. My bike was a little heavier and my gear a little lighter, but overall it was a similar setup. I definitely found it to be faster, easier, and more pleasant.