Yes, Prior to ordering an AT VistaScope, I tested identical screen material with and without the AT microperf 2 applied.
Effect on the sound of a non AT screen is, predictably, utterly catastrophic.
Intelligibility is destroyed. Imaging, separation and soundstage is completely trashed. Its exactly as you would expect. Its like putting a heavy duty trash liner over your speaker
The effect of ATs is minimal and is exactly known for each screen material and perf.
I put 3 Genelec 324As behind one. The results were devastatingly good. Off axis performance was not an issue.
For those asking about the effect on the sound, if properly installed, your looking at around 1db at the higher end. Spectral decay (RT60) remains unimpaired.
Make sure nothing, at any masking position, blocks tweeter LOS to seating position and all should be well. AT masks are available anyway.
Hope this helps