My Copley & Boegli flute just turned ten years old this month, which seemed like as good an occasion as any to upgrade my case. The new case by Northwind is beautiful and effective, and my measurements turned out to be accurate (phew)--it's a perfect fit! Not very visible in the picture is the wonderfully made Altieri case cover, which provides additional insulation, portability, and a pocket for cork grease, cleaning rod, etc. I also had a Humistat humidifier and hygrometer installed, since I live in a very dry climate.
Price was about 15% of the cost of the flute, which is a lot more than the pistol case I was using before, but the new case is a better aesthetic match to its contents, offering function and form.
All in all, it's a wonderful set, and both Northwind and Altieri provided excellent customer service.
And in case you're wondering, the embouchure insert is mother of pearl, installed about two years ago (the first--only?--one Dave has done), and it plays great!
But humidity around the flute is humidity, no? (Even if it's not specifically in the air.) And the thing is designed to be used in instrument cases, which tend to be velvet lined. Seems to work for plenty of people: http://www.humistat.com/Humistat_Testimonials.htm
