I'll chime in since I'm offering RSD as an option on all quilts. I have several quilts with RSD including a 30*F TQ/UQ M50 combination that I've used in some pretty wet conditions. First, no down will be waterproof, if you get it wet it will not perform. For that matter no insulation will work when wetted out. It's important to properly pack and protect your gear no matter what the fill type. Wet gear on the trail is no fun...
My observations on RSD and its benefits primarily are in regards to retaining loft. I used the TQ/UQ combination on my week long trip to Olympic NP. Weather was crazy dry for the rain forest so no really humidity to note. One thing I did notice was that the quilts retained their loft over the course of the week. Normally, as the week progresses, I can see the effect of body mositure on the untreated down resulting in a loss of some loft. The repeated packing and unpacking that occurs backpacking without a proper way to dry the quilts compounds and results in less loft as the trip goes on. I did not expereince that this past trip, RSD retained most if not all of its loft for the week.
We did make it to the coast for two days and one night, weather was misting, foggy, and humid, PERFECT for the coast. Outside of quilt shells would condensate moisture, it was pretty darn humid. I didn't notice any ill effects on the loft of the quilts in these conditions. Still seemed to retain their loft and no noticeable clumping. I did inspect other party members quilts and notice the untreated down had mositure related loss of loft and clumping. This was towards the end of the trip so the high humdity of the coast and the week long exposure to body moisture appeared to have added up.
Other trips out with RSD have been rainy weekend again, quilts retained their loft nicely, I'm sure M50 shells help slow mositure migration into the down but I'm also confident that the RSD performs better in these wet enviroments.
I've done a few small scale tests of the down resistance to water, we've all seen the videos, but I don't think that is a real world expectation that the down be water proof.
There are also other benefits to RSD other than its hydrophobic ability. With the resulting additional wash, dry, & sort in the processing of the treated down it is cleaner than untreated down. It also appears to be of higher quality when comparing equal fill powers. The extra drying appears to sort the down again resulting in much high cluster counts compared to untreated down. For the extra minor cost all of these things add up and make it a bargain for the benefits. I know for myself all of my future quilts will be filled with RSD.
Just a note, I'm a one man shop with no big budget for R&D testing so these are my observation from the field as a user and as a vendor using the product.
Last edited by sr1355; 10-22-2012 at 16:30..