I installed one, and unlike all the others, am quite disappointed. But, I plan to eventually solve my problem.
I got the shield not because I had any problems seeing the panel - even in direct bright sunshine. I got it because I could see the panel in the canopy. Now, I see the top surface of the glareshield - especially the stiffening ridge that runs along its length. It's very prominent and visible. I can still see the lower part of the panel in the canopy too - the throttle/choke knobs etc.
I prep'd my panel by sanding, priming and painting. I selected a flat black Rustoleum rattle can product touted for this use and its can states "Non-reflective." I applied several coats and thought it looked a little on the "glossy" side. It's not "non-reflective."
Since then I have become much more knowledgeable on this subject and expect to eventually find something which will remove the reflection. I found out that Coating reflectivity is a BIG subject with dozens of measurements. There are special paints that are used for the inside of telescope barrels that are regarded as truly anti-reflective. There are also flat paints that can be mixed with flour, poppy seeds, and other very small granular solids - these grains break-up the reflection angles by scattering the light rays to destroy the relection. There are also various coatings and coverings, like black felt that can be used that have a similar effect as do the granular paint additives.
The one thing I learned from these various forums and websites is that "flat black" paint ain't flat - not even close. I'm actively working this, have ordered some materials and will apply them. When I solve this "problem", I'll post the results here.
Actually, I had not planned to post on this subject until I had a solution in hand, but thought I would chime in at this time. If I come up with something promising, I may apply it to everything in the cockpit. I like to take airborne pictures, but so far have an enormous collection of pictures of canopy rails, sticks, stick grips, , my hand, wristwatch etc etc.
Bob Bogash
N737G