If there were a problem with the hydrophobic down, I suspect the real scientists and pretend scientists throughout the backpacking world would fiercely attack the coating. However, the MH Ghost Whisperer is almost universally regarded as a good product. it will either loft over time with use, or conversely, it's just less lofty as you expected and performs at spec like that. I suspect the former, personally.
The nice thing about the backpacking community is that the serious backpackers DEMAND serious gear, and the casual backpackers fill the non-serious gear quota. So, companies like Mountain Hardwear sell 20,000 heavy 700-fill down jackets and just 1,000 nice, 850-fill ultralight jackets and the ultralight ones HAVE to be good, or they won't sell. Market-driven innovation and competition is real for serious backpackers, and has been for a while, I suspect. And the companies making this stuff get to play the game to get the serious backpacker's dollar because their casual quota makes taking chances and failing acceptable.
This is just the way I see it, I'm no expert. But it's fun to think about. Would we get things like the BA Fly Creek, too small for most humans, or things like the stove that charges iPhones, if the market didn't naturally accept chances? Probably not!
I have digressed…