As I have said before, due to school and family responsibilities, I am only able to take 1-3 day trips at the moment. In the future of course I fully intend on doing thru hikes, but for now I have to make do. I was able to get out for 18 nights in 2011, which is not bad, though it was not enough to satisfy me all the way either.
Anyhow, when I go out with friends or family, and they ask about LW/UL/SUL, I am happy to explain the point of it. Something that comes up often from skeptics of our whole methodology is: "But you only go on shorter trips, so big deal if you take 10kg of gear? It's only for a few days that you have to suffer the weight."
I suggest that it may be even more important to go lightweight for shorter trips than for say thru hikes. Because I have a very limited amount of time, around 24-72 hours, I want to do as much as possible while I am out in the woods. I want to go deep into nature, first of all, so I can see animals and get away from it all, for example. This requires longer hikes, which takes more time. When I pause, be it to make camp or just a break, I often want to fish, swim, gather natural food like berries and mushrooms, etc. This also takes a big chunk out of my time and energy bars. If I am exhausted because I am hauling 10kg up and down hills, I am not going to be able to accomplish my set out goals.
On a thru hike, in theory you have more time to spare, so you can have a zero day to devote to whatever you want, if you can afford to have a zero day that is.
A really nice plus of overnight trips is more flexibility to cut down on weight if the weather is ideal and you plan ahead. I will check the weather obsessively a few days before a trip to see if I can ditch my rain gear or not, sometimes ditch my shelter too.
Though I do envy you thru hikers, but I will be there soon enough. Which reminds me, I know about the Triple Crown of backpacking (AT, PCT, CDT)--but is there a Triple Crown for other continents? Like is there a European one?
Anyhow, do you go lighter or heavier for overnighters and other shorter trips? Why or why not?