Bulldog,
I've been carrying the same stuff during the 3-season for the last 5 years or so with little variation. I've froze my rear end once...on the summit at dawn in '04 and one night in October 2008 at 11,000' when I was too lazy to carry an extra sleeping pad, which was in the car at the trailhead...that's it. Last summer, I don't think I used my 3-season down jacket but once...on the summit of Mt. Whitney. It does make one heck of a pillow.
About the only adjustment I make is to add one of my microgrid fleece tops and an extra pair of mitts for pre-dawn 14,508' summits...that and what flavored alcohol goes up the trail. The nice thing about backpacking is that sleeping bag is one heck of a piece of extra clothing.
