I do the same as sapper1, normally.
Before I moved to Scotland I had to leave the country to do any camping, which always meant I preferred to carry normal clothes as well as the trip would combine all sorts of things. The more varied the itinerary of my trip the more kit I had to carry unfortunately...
whats more, the environments I was hiking and camping in were never familiar, so I never knew when I'd next have water (so chose to carry several extra litres.. extra everything really)... Also, in whatever country, if you want to stay at a payed campsite till you get where you want to go, you may have trouble getting by with your bivy bag and tarp, it means all you kit is lying about and easily stolen when you go to shower or brush your teeth. so I have to take a tent. not all environments can accommodate a tent, so I have to bring a bivy bag... so it all starts to add up for me. anyone else recognise these issues?
Living and camping in the same country means I can keep the weight manageable, and make up all the weight I save with careful gear selection with a lot of food and new gear that I want to test.
Climate is a big factor as to weight I carry. Some places like in the Rockies I've had it go from -20 Celsius and snowing on one day, to a warm and sunny +7 two days later. All that cold weather gear then has to be carried in my pack rather than on me, and seeing as my kit is mostly wool, it can get quite bulky. So my pack can hold about 110 litres.
All this very light camping is great, but my pack in itself already weighs 4kg (external steel frame), so I tend not to think about weight too much as its heavy to begin with. If I need to bring something I will, after all I need it. I've gotten my pack lighter over the years not by having lighter kit, but just by needing less of it, (the more you know etc etc )
In a group trip I still tend to carry the same weight/kit just because I feel uncomfortable relying on other people to remember it or not lose or damage it, each of which has happened at some point in the past.
My pack is a haglofs 'alaska', I've never seen anyone else with it, and I havent seen it for sale since I bought it. Its very straightforward, very strong, and I'm very happy with it. here's a picture for the curious (not my site, but the only one I could find that has a picture of it). If anyone has used one I'd be curious to know what you thought of it, I think its great.
http://www.nallo2.se/fjallbilder/diverse/minutrustning.htm