I, too, did the Sherwin-Williams satin paint and found it to be too shiny (as the article's updated info inferred). So, I used their "Duration" ultra white matte blend and got nice results. This was the paint the Projector Central article suggested, before them trying out the satin version (which was brighter).
I made a sample of the "Duration" paint on a piece of drywall and brought it over to a friend's home theater I helped do the install. His screen (Monoprice Ultra HD) is ISF certified and a gain of 1.2. It is bright white with very little sheen. And gorgeous.
The "Duration" paint's color balance was precisely the same as his ISF screen. However, the gain was lower and your eye noticed the difference in 100 IRE tests.
After this test, I again thought about the "eggshell" option (similar to satin, but just a tad less shiny). I tried Dutch Boy's Ultra WHite eggshell against the "Duration" paint from Sherwin-Williams. It had identical color balance, but was a full f-stop brighter (from a DSLR light meter).
Although I have not tested the Ultra White eggshell against the ISF 1.2 gain screen, I have a hunch it will be really close to its gain. I already expect its color balance to be accurate.
I'm pretty sure that the extra brightness came from the eggshell finish over the flat finish.
All tests were with the 5040UB.