We have actually been through one winter already. When I was building the house I didn't have time to blog about it too so I just took pictures and video with the intention of blogging when I had the time. So far no issues with condensation on or in the ceiling. The key is that I sealed it to the point of having no airflow both on the inside and the outside. No airflow means that no moist air is entering the ceiling to condensate.
I am a roofing service tech and deal with condensation related issues in attics a lot during winter so that is how I came up with the idea. Another way to look at it is that it is acting more like a flat roof then a conventional roof system. I think the biggest draw back to this system would be that the shingles probably get hotter without the airflow from below and will probably not last as long.