For audio I have an Anthem D1, P5 amp, and Studio 100 v3 mains, and a Denon 3910. Video is a Infocus 777 with a Panamorph U380 for scope viewing. Not the best but nice enough for me.
I have an SMX screen on a "hinge" so that I can flip it up and out of the way. Allowed me to preserve access to a storage room and so moved my max screen size from 113 width to 130. So I can in less than 60 seconds swing the screen out of the speaker path.
I will be the first to admit I do not have a "golden" ear, mine are 48 year old which says enough, but I digress. I don't hear any difference between with and without the screen in front of the speakers. I have listened to probably 100 plus hours of new and familiar content and never once thought that something did not sound the way it used to. I said it that way on purpose, I have had these speakers for several years in the same room. My setup may not sound "right" in the studio way, but the SMX did not make it sound different, which is the way it is supposed to work.
Moving from a blackout cloth screen to the SMX did not magically improve the immage, but it certainly did not hurt it. No faults found there.
On the other hand moving the speakers from beside and below a 130x55 screen to behind it significantly improved the experience. Highly recommended.
I also endorse getting a screen that will last thru multiple PJ's, it is significant enough of an expense that unless you are trying to "fix" a PJ problem (needing a gain or grey screen for example) getting what you really want the first time makes sense. A big reason I went with the 777 PJ is that it did not have any problems other than being 720 to compensate for.