Both of the previous replies raise valid points, especially about simplifying your trail life and leaving stuff behind. I tend to be one of those who is always looking for ways to go lighter (it's almost a hobby in itself), but I've gotten less concerned about it lately. In fact, I recently changed out sleeping pads to get a higher r-value for the same weight - then discovered that the chair kit made for the pad was the most functional chair I'd ever seen. It was half a pound heavier than any other chair kit I'd used. However, as long as I can keep my total pack weight at or under twenty pounds, I may very well carry it, just for the sheer luxury. And in the winter, when I tend to take shorter trips, I may just take it anyhow, so I've got a comparatively warm spot to sit.
I'm very comfortable anywhere under 20 pounds; the extra half pound doesn't seem to matter. Go over twenty, and it does. That chair kit equates to a day's food; on a trip to Isle Royale for a week, I doubt it would go. But Ohio's Zaleski forest, for a two-night trip - you betcha!
The one area that I do try to work on, where saving a pound makes a difference, is my ongoing weight battle. I regularly fluctuate between 190 and 200 - and each extra half pound is noticeable there. (Of course, that may be that I'm doing more daily walking when I'm down around 190, so not only am I lighter, but I'm in a bit better shape, too.)