Roger, I believe it can dry quicker. I just hope the process doesn't "dry" a feather out by removing the lanolin-like oils, replacing them with it's own version of water-proofing.
* Carotin is the same family as mammal's finger nails & hair. Anything that protects the feather from water will help it reduce overall water uptake. Less water means faster drying.
* Any drop that forms on hydrophobic down will evaporate faster, since it can evaporate from the entire surface area, not just the top as would happen on a normal, wet feather...faster drying. Of course, the shape of the droplet also plays in to evaporitive surface area. At some point in volume, a sphere and flattened oval evaporating from a single side will bump into capilary tension, so, there is a basis for saying it dries faster. How much...well that is debatable...depends, depends.
Of course, you and I know the numbers are fecetious, simple marketing hype. It would depend more on atmospheric conditions, shell material, and type of drying. They could be measiring to FULL dry of actual water, or FULL dry of the actual plume's humidity, which would take far longer and could actually be inhibited by any coating. Want to guess which measurement they are using?
* Loft vs Weight might stay the same. For example, if they use a 850FP down, treat it with whatever and increase its loft to 1000FP (as claimed), they could rightly say it got lighter at a 10% increase in weight, since the overall loft, about 15%, went up faster than the weight increase. Of course we know that loft is just one component of a fill's overall warmth (likely due to increased static repulsion, ie like charges repelling each other?) Quantity (weight) also counts, so, I am discounting the difference of 5%, calling them even. After all, who would believe me if I said I coated some feathers and made them lighter? Easier, and more accurate, to say I coated them and gave them better loft.
Outside of a lab, is this usable loft? I don't know. Insensible perspiration may contribute enough humidity to negate static repulsion, simply leaving the heavier coating. Something even the EN standard doesn't account for either. Or, if the coating stiffens the actual plume, it could make it brittle, breaking it in use and during comression...a durability issue effecting a bags longevity, perhaps drastically. $300-400 for a bag that will only last 5 years for a dubious 5% performance increase is no bargain to me. Synthetics are cheaper. It might be subject to increased attractiveness to oils and dirt...a reliability issue when I am out for two weeks. And, dust may accumulate quicker, due to an increase in static charges. Body oils will be attracted quicker with some non-polar materials than with water...a maintenence issue.
So, I will NOT be the first to try this stuff. Whatever the marketing hype says. There are too many questions in my mind to say it is better or worse.