I've done some crude calculations to figure out the weight of the insulation in the new Climashield quilts. The standard quilt with two layers of .75 inches loft seems to have about 3.5 oz per square yard insulation which is then doubled. This is really just an estimation because the quilt with the gorget and draft stopper is a really irregular shape. According to my figuring, 3.5 oz would be about .75 inches of loft so it would make sense.
I've heard that Climashield is a better insulation and doesn't need the same loft to achieve the same warmth but I'm suspicious. Insulation is all about trapping dead air space. It's a balance between the amount of air you can trap and how well the insulation can keep it in place (i.e. the air can't flow around inside the insulation). However, loft seems like the bigger factor to me. To keep air from moving around inside the insulation, it generally needs to be denser. Having had the chance to directly compare scraps of both Climashield XP and Polarguard 3D I think Climashield is much denser but even though the individual fibers are thiner. When you look at various types of insulation, the denser the insulation is the less weight efficient it is. This (as far as I know) is true of down, synthetics, foam, aerogel, etc. Even if you look at different fill powers of down, the higher the fill power (less dense) the warmer it is for the same loft of down. Therefore, if the main criteria for insulation is light weight, then the goal should be the least amount of weight for the most amount of loft.Polarguard 3D does achieve a higher loft for less weight. I don't think there will be some great insulation that achieves low weight, low loft and big warmth.
I also have a theory that insulations that are thin and dense can be tested in labs in such a way that they provide inflated specs. Take a look at aerogels in Pacific Outdoor Equipment pads. The Hyper High Mtn Sleeping Pad has a stated R value of 20. However, if you look at the real world reviews of the pad a few people have said they don't really notice much of a difference over a therm-a-rest and closed foam pad. If you've ever had a sleeping bag or jacket made from Thinsulate you might have found that it doesn't insulate much better that any other thin insulation. These examples make me think that there's some laboratory tinkering going on.
Another thing that is not taken into consideration when looking at loft vs. density is the breathability. Breathability never seems to be taken into consideration in tests of insulation. If an insulation is denser it stands to reason that it wouldn't breath as well causing it to be less efficient.
Basically, I'm not convinced that Climashield XP is better. The fact that Polarguard is no longer available seems fishy to me. It's under the same umbrella as Climashield but it doesn't really make sense to me that they would get rid of it. They didn't get rid of 3D after Delta came out and they didn't even get rid of the original Polarguard until it became unprofitable. Given how many product were using Polarguard I highly doubt it was unprofitable. I suspect that the demise of Polarguard has something to do with the fact that Climashield Combat is used by the U.S. military. I figure some deal went down with the military that meant Polarguard had to go. If the military helped finance the development of Climashield it may be entitled to some of the profits. They would would have wanted to kill Polarguard to replace it with the profitable Climashield. But enough conspiracy theories for one day.