I wouldn't touch a "treated" down bag with a 20' pole.
The jury is far from in on its performance. Top tier makers like Western Mountaineering won't use it. There's no way I'm wrapping myself in another damn chemical for an 8 hour sleep...
After looking at it for a couple years it appears Western Mountaineering, rather than jump on the latest fad, has made it's final decision... from it's FAQ Page:
We have found in our own testing that the performance enhancements of hydrophobic treatments on high quality down are widely overstated. High quality untreated down already has naturally water repellant oils on it left by the geese (makes sense since geese spend a lot of time in water). These oils help repel water and keep down lofted. More importantly is that these oils last indefinitely. Hydrophobic treatments wash out like a DWR and remove the natural oils during the application process. Because of this, and the water resistant capability of our shell fabrics, we feel that hydrophobic down does not provide a considerable impact on performance and could actually inhibit performance over the lifetime of our products.
