I have now taken multiple trips with my D700 to Europe, Australia, Iceland, etc. In each case I tailor what I bring to what I intend to shoot. I also try to keep my total weight of my camera bag, a Tamrac Pro 5, sometimes with one external lens case to 11 lbs roughly the 5 kg you say you carry. I DO NOT carry an external flash as in most places I have been you can't use them anyway and the built in flash works in most instances where I needed it and it was allowed. So my MUST HAVE lens is my 17-35 f/2.8. the majority of images I make can be made with that. I do not carry a tripod, pretty much for the same reasons as the flash. With the D700 I have rarely missed a photo without it. I will start taking a table top and see if it gets any use. My next MUST have lens is my 35-70 f/2.8, but sometimes it gets left behind. It was replaced by a 70-200 VR when I went to Iceland because I planned to shoot Puffins. I usually never carry the 70-200. Lately I have been packing my 85 mm f/1.4 lens as it is great in theaters and interiors and I carry a Kenko 1.4 TC that I use with this lens and the 35-70 as I have found that generally this is the most reach I need a 119 mm and it is still a fast lens combo. Finally I throw in my 16 mm Fish eye because it is so small I can even put it in my pocket. The other stuff in the bag is my CF cards ( I usually leave most in the hotel safe and carry one or two, I DO NOT EVER bring a computer or a backup drive as the CF card is virtually indestructible while the other things are not. I carry one extra battery. The charger stays in the room, I carry a polarizing filter, a remote release, a small flashlight. I usually have my bag slung across my chest, and keep my D700 out and on my shoulder with an Up Strap. This tends to work fine to distribute the weight. I do not take a camera backpack as I find them awkward to work out of and I have a Lowepro like you. I also find they tend to make your back sweat in hot weather. I do take a photog vest and will wear it if it is not too hot and then I can stuff thing in the pockets and not in my bag. I am considering trying a belt arrangement as another way to carry my gear. In general I agree with others here that the best way is to consider what you will be shooting that day and bring only what you need. If you have a kitchen sink mentality you are only asking for back pain. For me P&S cameras don't cut it. I know the D700 seems heavy, but a little weight training will make it feel light. As you say you came back with great pictures. My last trip on the Rhine and Danube I saw all kinds of Nikon's with Big lens and tons more P&S and I was the only one getting images in some situations because of my fast lenses and great ISO performance of the D700.