First, our initial thoughts were to go with Primaloft. It's a good insulation, it has great penetration as a premium fill in the lightweight alpine insulating clothing market, and they do great marketing on that brand. When someone says 'Primaloft' they think: the best wet-weather insulation on the planet. It's a no-brainer, right? And, it feels great - sort of like down, even - very soft, very compressible. I have several PL1 and PL Sport pieces and really do like them.
But Kosa got wind of our Cocoon project and sent us some Polarguard Delta samples, so we decided to make some of the Cocoon prototypes out of it. We split them up and sent them into the field for three months this winter, and played with the two insulations in our testing lab as well. Here were our conclusions.
1. Loft:weight ratio. Polarguard was higher than Primaloft PL1 - as a dry insulation, Polarguard provided more warmth for less weight. Keep in mind that these tests were performed with uncrushed Polarguard Delta, which is what is going to be used in the Cocoon.
2. As a wet insulation, Polarguard Delta did absorb more water when completely saturated, but it was so easy to ring most of that water out and restore the loft - 90% of its original loft. With Primaloft PL1, it absorbed enough water to completely collapse the loft and after ringing out the insulation, it 'sprung back' only to about 30% of its original loft. So, in catastrophically wet circumstances, my money is going to be on Polarguard Delta. One of the arguments that Primaloft has is that it absorbs less water than Polarguard. The test they show you at the trade shows - and it certainly convinced me initially - is that if you hold PL1 under a running faucet, water just kind of rolls off and doesn't go through the insulation. If you hold Polarguard Delta under a running faucet, the water runs right through. What do you think about that? Primaloft is thus water repellent, right? So we got to thinking about it and here's what we did.
3. Cost. Primaloft PL1 is a clear winner here. Not in the cost of the insulation so much as the cost of working with it. Primaloft (which is scrimmed) is far easier to work with than unscrimmed Polarguard Delta. So, there is some manufacturing labor involved in using PG Delta. In addition, we could buy Primaloft in small lots that make it pretty risk-free. With PG Delta we really had to get them to buy into the concept in order for us to use the PG Delta in our products. There was a lot of negotiation involved, and up-front time investment. We showed them prototypes to make sure the insulation was going into garments that really reflected the quality of the Polarguard brand. Fortunately, they were very pleased. I didn't understand this two years ago, but I certainly do now. They do not want to dilute their brand image or product quality by throwing it into a product made with other materials that are crap or into a finished product that looked like it was made out of a garage (not that all garage products are bad! Finally, PG Delta in a 60g weight, which is also the PL1 weight used in the Berghaus and MEC garments, is pretty much only available to those willing to purchase a custom run of it - 1000 yards, as it's kind of just an experimental fill weight for them right now. And so, we now own a lot of Polarguard Delta 60! At any rate, this is OK, because we are also using it in overbags that mate with our Arc X down bags.
4. Be the best. Obviously the better economic decision was to make the garment out of Primaloft. But the benefit of going with Polarguard Delta is that we have the blessing of the company, they are working very closely with us to help make the absolute best garment we can, and best of all - it will be lighter than anything we can do with Primaloft PL1.
5. Durability. When we pulled all of the garments out of the field - and granted - these were used very hard with a lot of re-stuffing - the PL1 garments had on average about 50% of the original loft, and the PGD garments had only about 25% less loft than when new.
In short, I think Primaloft really is a great insulation under most circumstances. But I also think that Polarguard Delta has the technical edge in both warmth:weight and water management. We are making the Cocoon to set a technical standard and we want the best possible materials in there to create a garment with an incredibly high warmth:weight ratio. FWIW, using Pertex Quantum and PG Delta, we have a long sleeved, high collar, pullover garment that is warmer than an equivalent 850-fill down garment (which to meet the weight spec of the current Cocoon must be non-baffled) made to the same weight specification - which was actually the first generation Cocoon prototype. Down gets more beneficial as you increase the loft of the garment to the point where you can begin to baffle it.
A little about the current similar pullover garments on the market, especially those from MEC, Berghaus, and Patagonia. I've used them all and they are all excellent. The MEC Northern Lite P/O in PL1 hits a great price point and has some nice features. I think my M is around 12.4 oz. The Patagonia Micropuff has thicker PG Delta in in the body, weight in M is 12.7 oz, so it will be a little warmer than the Cocoon. The Berghaus piece is 10.2 oz, size M, and uses PL, so like the MEC P/O, it's not going to have as much loft as the Cocoon. However, the MEC and Berghaus pieces are more compressible - if you have a tiny pack and space was really at a premium, you might consider this in your purchasing decision in favor of a PL-filled garment.
Is Polarguard Delta 'better' than Primaloft PL1? PL1 still has advantages: it's cheaper, it's more compressible, and it "drapes" better. I think it would make really nice high loft insulating long underwear! And because it's thinner, you can do some neat stuff with it in less bulky insulated constructions - like Cloudveil's new soft-shelled PL1-insulated Zero-G insulated ski jacket. But PGD beats it for warmth:weight ratio, you can ring it out in a catastrophe and restore most of its loft, and appears to be more durable (where durability = ability to maintain loft over time and use).
FWIW, when we were prototyping this garment, we made some that were unscrimmed, uncrushed, with virtually zero features, just to see how light we could go on a p/o garment that had 60g fill, a 1/2-zip, straight hem, elastic cuffs, and a collar. The weight of those garments in a M: 6.8 ounces in PG Delta, 7.9 oz in PL1 (which requires a scrim and more aggressive quilting since it's a short stable rather than continuous filament), and 7.8 oz in 850-fill down. So, we are likely going to take that 6.8 oz garment, and add a little back to bring the price down, since the cost of manufacturing that one would have required a retail price of $219. However, I expect the final shipping version of the Cocoon to be 7.9 to 8.1 oz in M, a little lighter than our 8.5 oz goal.
So, I hope that answers your questions.