Thanks for taking time to respond. I know you know a lot about lighting and photography in general so I was a little curious as to the placement of the dish in your setup for testing. I know there are no rules when it comes to photography and light is light. However with that said, I would think the testing position would at least be close to the position of which that particular modifier was designed for.
I wanted to let you know a few things about a BD. It was designed for high fashion photography I am sure you know that to some degree. The beauty dish was built for a specific purpose. That purpose was to suck in the cheeks of a model. The beauty dish creates contrasty not specular light for for people who have faces with nice symmetry and angular features. You want to make sure the model has lots of make up or great skin because the kind of light the BD creates will show all imperfections, like holes or bumps. Get out the bondo if you have to but make that skin smooth so the light doesn't show off all the imperfections (saves a ton of time in post).
More, the BD will also flatten a high nose and will sure put a shadow behind the cheek bone creating more of a 3D look. IMO it is perfect for narrow or thin and faces. The reason is in how it casts the shadows, the shadow density and the feathered edges of the shadows are. It's perfect for semi skinny models. A word of warning if you use it on a model that is too thin, it is going to make her look worse. Her already sunken cheeks will be really sucked in and it is not flattering at all. The shadows will look real bad.
Also don't try to use it on someone with a round face, it will make the face look even more round along with flattening their nose into a pancake. As a general rule when using a BD you will use it in a butterfly position. In that position, it will let you test the dish for it's intended purpose. In that position you will see what I mean about sucking in the cheeks.
I really liked your testing and effort put into this thread. I wanted to let you know a little information about a BD . Like I said before there are no rules in photography, but if you try to use with its intended purpose in mind, you might see results in a more dramatic way. Again standard position is slight camera right or left in a above pointing downward to create the pattern of light I described above (butterfly).
I hope this info will help in in choosing to or not to use a Beauty Dish, and if you do how to use it in a way for which it was intended. I don't use them much. I have found I can use a soft box careful and positioning can achieve much the same look. All without showing all the sink imperfections. I do have a speedo 22" and will use it when I have the perfect girl, they are so few and far between. I always find myself dealing with regular people (not models) and trying to make them look good. The BD will never help 99% of the ones I shoot. So it sits in the case most of the time.
Last thing, it does make a nice catch light doesn't it. I have been experimenting on a LED double row of lights in a circle pattern that wont influence much of anything to the scene, that can be used for a round catch-light creator. Have you seen Tron Legacy? There is a scene where Sam ( a main character) gets his disk. One of the models goes and gets his disk and when she picks it up she has this awesome ring catch light but it doesn't seem to affect the scene, just a cool catch light. I will post it for you to see.
Edit to add the image and fix typos
Looking at this as a still it looks like she has contacts in creating that catch-light. Hell I don't know, it looks cool in the movie, LOL
I will take that image down in a day or so, after you see it. I don't like to use copyrighted content, in this case for educational, I made an exception. It will be removed!