I've seen the Elite Black Diamond, DaLite Parrallax, DNP Supernova, and a couple of others.
I've been to trade shows to see them as well as have seen them installed in professional applications.
In all cases, the screens suffered at least somewhat from hot spotting, image uniformity issues, and sparkling.
These issues are not insignificant when you are talking about trying to get the best image in a room which can simply close a door and turn the lights down. In situations where people are watching a movie (critical viewing) there is rarely a time when the room lights need to be on, and simply turning on a low-level directional light at the back of the room will not significantly impact the on-screen image. The key is to have directional lighting away from the screen in a dark room to leave excellent results in place.
Keep in mind the price differential between a ALR screen like a Black Diamond and a standard white high quality screen can be $1,000+. This isn't a small matter to consider.
Also bear in mind that if there is sparkling, hotspotting, and image uniformity issues, those aren't going to go away when you turn out the lights. In fact, creating 'ideal' movie viewing watching conditions will only make those issues more prevalent.
I swear, there is NO WAY I would ever recommend a ALR screen to someone who can just make their theater dark. It's find for a living room. For a rec room with windows. But in an actual theater space where light can be controlled? I just don't get it.
I'm stepping out of the conversation as the ALR fanatics continue to try to play down how things like sparkling in your image don't actually matter. I'm going to go take a baseball bat to my LCD and tell my family that the giant cracks I've created are just part of the experience. (/sarcasm)
Really, if the goal is the best image possible, then the experts at DaLite, Draper, and Stewart will tell you to put a white screen into a good room and call it a day. With that being their top statement not coming from the marketing department, then perhaps that should actually be the top talking point goal instead of the ALR marketing machine. If you like your ALR screen, great, but please be honest about how it negatively impacts your image.
The only video I've seen online of a ALR screen with the camera moving around, clearly shows the hotspotting issue which ALR screens are notorious for.