One of their experts gave a talk at our regional bee association last year. A few members were giving him the evil eye, but I personally found much of what he had to say useful.
I reserve judgment over their evaluation of their own products. I believe, however, that they are undeniable experts at spotting other causes of bee death and disease. Some of their methods for spotting disease are fairly easy to do, and I intend to do the same. In particular, they put a screened board IN FRONT of their research hives, elevated a little off the ground. Bees tossing out their dead will leave many of them on this board, where they may be conveniently counted, and collected for autopsy.
What a simple idea! And useful. Listen to what they have to say about methodology.