To me, the biggest question mark that still remains is whether the treated down is as durable a non-treated (i.e. regular down). Since well cared for non-treated down normally lasts for decades (which is one of its greatest assets), we won't really know a definitive answer to this question for many years.
It's basically a guessing game at this point as far as I can tell. Anyone who has tried to convince me otherwise seems to be selling the stuff and is therefore highly biased.
Down is naturally hydrophobic to begin with (remember, it comes from water fowl), so the treated down technology seems like a fairly marginal advantage to me in practice.
We also don't know how the treated down handles washing versus regular down.
I'm trying to remain open minded about treated down, but my gut impression so far is that its mostly an up-selling strategy by gear and apparel companies to try and get you to spend even more money on (already expensive) down products.
Until proven otherwise, I'm not biting. I've never had a problem with down getting wet in the first place (I prefer to only use it for sleeping bags), so this treated down is a solution in search of a problem for me personally, but YMMV.