Wiggy is wiggy, but he does say a lot of true things.
Let's get one thing straight. I'm assuming we are talking about what works in the field, not in a laboratory. Yes, the R values in the wikipedia article are different for the same loft. For some of those materials, such as closed cell foam, I have already conceded that loft doesn't tell the whole story. But consider something like loose cellulose (more or less shredded paper). The R value measured in the laboratory will be the same R value if used for building insulation (which is its purpose), because the insulation is never abused, meaning never stuffed into a stuff sack, carried around in a backack, unstuffed, etc, etc. But how long do you think the R value of loose cellulose would be retained in field conditions if used in a sleeping bag? Not very long.
So, yes, you can goose polyester in various ways to get some added R values either per oz or per inch. Either you fluff the stuff up real lofty or else you make sure to cut the fibers real fine so they block convection currents. And the final result is something really flimsy which loses loft really fast in the field. There is the problem.
Everyone who has used synthetics extensively in the field has come to the conclusion that continuous fiber works best, because it is most durable. The other synthetics tend to break apart and then you get huge cold spot. Wiggy has lots to say about this, though he exaggerates and lies at times. Most of the people on forums who criticize synthetics are talking about the non-continous versions.
As for continuous fiber polyester (Polarguard, Climashield), there really isn't that much you can do, given that the underlying technology is simply strands of polyester. This is almost 50 year old technology. Yes, you can make the strands thinner and thinner and hollow them out and make them funny shapes. And the result is something that has great initial loft and then loses loft rapidly because the thin fibers lack resilience. Wiggy has stuck with thicker fibers, which have much less loft per oz initially, but which don't lose loft so rapidly because they are more resilient. My impression is that Polarguard 3D is better than what Wiggy uses, at least for quilts, but you do have to take into account the loss of loft with 3D. That is, if you want a 3-season quilt roughly 2" thick, you need to start with 3" or 9oz/sqyd of 3D, or 11.2 oz/sqyd including 1.1oz shell fabric. Compare with 800 fill-power down, which requires about 6.5 oz/sqyd to give 2" loft (assuming 20% overfill, no-see-um baffling, 1.1oz shell fabric).
IMO, the only real improvement possible with continuous fiber at this point is to improve the manufacturing tolerances, so that there aren't all these variations. That doesn't improve R values/oz or loft/oz, but it does make for a better product. Obviously, this would raise costs as well.
"[munch] lost 27% of its original loft still managed to maintain 94% of its original insulating ability":
What this suggests is that the insulation had lots of air space but wasn't blocking convection currents well initially, and then it got compacted and had less air spaces but was blocking convection currents better. A sort of meaningless result, IMO. You really have to have very little field experience to believe that a bag which has lost a signficant amount of its initial loft will keep you as warm as one which hasn't lost loft. Once that LiftLoft bag loses 50% of its initial loft, as it will eventually, you can be pretty sure it won't retain 94% of its initial insulating capability.
One last thing: all reputable down manufacturers list loft, overfill%, fill wt, etc. None of the synthetic manufactuers list this sort of information, which suggests they are all dishonest. Furthermore, even though the manufacturer of Polarguard admits their insulation loses loft with abuse, none of the manufacturers of sleeping bags made with Polarguard point this out. The European standard was created because of all the dishonest manufacturers of synthetic bags. There was never much confusion with respect to the manufactuers of high-end down bags. The European standard is an improvement, but it still doesn't take into account loss of loft in synthetic insulation with use. You should probably add 20°F to the manufacturers spec for any synethetic bag to account for this.
Oh yeah, with regards to the military, I'm not defending the military per se by any means. The Natick Labs research was done long ago and it is confirmed by every intelligent study of insulations I have ever read, as well as by all my own field experience and what I have learned from other backpackers. I am not surprised that the military is continuing to fund new studies when previous research already gave the answers. Nor would I be surprised if the researchers contracted to perform studies for the military take the money and perform the studies, rather than rejecting the money because there were previous conclusive studies on the subject.