Well, I am not ULTRA light, but I do like lightweight. After 12 years in the infantry, anything under 60 lbs is "light".
That being said, I STILL carry enough to get me through. I can pare my pack weight to about 20 lbs, with food, no water. With a full camelback, maybe another 4 lbs. Thats pretty darn good.
Now, I always have a tent, a 20° down bag, a fleece jacket, wet weather gear, a hat, stove, an all the accoutrements. I just buy the lightest I can.
Our SAR here consists mostly of finding alzheimers patients and folks who had no real right being out in the first place. People going camping in winter with a jean jacket and a 12 pack type of no business. So, ultralight doesnt really play a part in it, unless you count what we carry. But, then againm we KNOW where we are, and have others with us. So, we can afford to go super-ultra-light.