Using fixative with pastels, yes or no?

I'm often asked if I use fixative when I finish one of my pastel paintings, and I am emphatic in my big fat NO response. Here's why: 

There are multiple reasons why I don't use fixatives,  but the main reason is that I don't like what fixative use does to the appearance of pastels.

​Hope springs eternal, though, and I still was hoping to find a way to use a fixative or varnish to make a pastel without the need for framing the work behind glass. 

With that in mind, I purchased art panels that had a rough texture. The advertising copy indicated that these panels were perfect for pastels, and that an artist could varnish the pastels on these boards and frame them without glass.

​Hearts and flowers danced in the air at the thought, and I couldn't wait to try it out. ​

The panels were only 6x6 inches, (see below for what I used) so my commitment was minimal. I also understood that the work that I was going to make would likely be sacrificed once the varnish was applied. In other words, I knew that the work could be ruined, but it was all in the name of potential progress. ​​

These are the panels that I purchased for this experiment. 

Here is the little pastel painting prior to my use of varnish made for use with pastel. 

From the photograph of the painting above, you can see the luminosity and subtlety of the colors that is a characteristic of pastel pigment. 

Now look! After using multiple layers of varnish to ensure that the pastel wouldn't smudge, the luminosity is obliterated. See how much darker the colors are, and also how the complexity of colors is no longer apparent? 

Now, I know that I could reestablish those lights and add more color to the piece, but that would defeat the purpose of using a form of fixative to be able to frame a pastel without glass.

​Sigh. I will continue to not use fixative, and continue to use glass when I finish my pastel paintings. 

Now it's your turn. Do you use fixative? Why or why not?