Primary Arms has two micro prismatic sights at the moment, both of them part of their SLx product line. I've got a video on these coming shortly, but I have been slow with editing, so I figured I should lay the groundwork, so to speak. I added them to my updated recommendations, so some additional commentary seemed like a good idea.
I have spent quite a lot of time in the last year or two trying to think of a variety of ways to set up AR-15 rifles. I sorta know how I like to set them up for me, but that does not necessarily translate in how I think they should be set up for others, for example for my wife who is eight inches shorter than I am and less than half the weight and for my kids (8 and 10 years old as this is written). To be fair, my 8 year old son will probably be bigger than I am before I know it, but in the meantime I need to set up something he can grow with.
The fashionable thing, of course, is to set everything up with LPVOs and offset red dot sights. That is not too dissimilar to how I set up my AR (see the second Guns of the Dark Lord video), except I use offset irons and, for me, those are really supplementary sights. I use the Razor Gen3 LPVO on that gun on 1x all the time.
My wife has taken a couple of gun classes with me. She seems to like the classes (or at least likes them enough to go with me sometimes and develop some proficiency), but she is not a gun enthusiast. Also, when we are home, making her practice requires political skills and powers of persuasion I do not possess. It is easier to take the kids with me to the range, but getting them to do structured practice can be a bit of work. Besides, I sorta want to keep it fun for them.
What is fun for people who are not yet (or will never be) gun nuts? Being able to grab the gun and shoot at different targets, at different distances, and do so without putzing around with equipment.
Given that I am also dealing with people who are physically pretty small, the whole setup has to be light ad maneuverable.
So, what we've got for the moment is: light, quick, accurate enough, easy to use with minimal number of controls.
Well, that sorta spells out some sort of a low power prism with an offset red dot and the lighter this whole thing is, the better.
What is low power? That's another interesting question. For speed, you sorta need something with unity magnification, but the drills I am setting up for training tend to involve taking a look at something before shooting it. There is a lot to be said about being able to go fast and I am really not good at the whole going fast thing. However, I can make a really good argument that we are not living in a video game and being able to recognize whether whatever you are looking at needs to be shot is as important as being able to shoot quickly and accurately.
For target recognition, a little bit of magnification goes a long way. My wife's AR sports Trijicon Compact ACOG 1.5x16S with Primary Arms' ACSS reticle. 1.5x may not sound like much, but magnification is multiplicative. It is roughly equivalent to the difference between 2x and 3x or between 4x and 6x or between 10x and 15x.
For me the range of "low magnificaiton prismatics" starts at 1.5x and ends at 4x. 4x is probably higher than most people are comfortable with for this kind of use, but I spent so many years shooting my Elcan OS 4x that I am supremely comfortable with it as long as the reticle stands out well enough.
After that whole preamble, let's go back to Primary Arms' new batch of prismatics. They have two SLx micro-prisms, 1x and 3x, and a GLx 2x that is more of a standard/large-ish prism design. It is still a very compact scope since prism size is tied to magnification and FOV. With 2x magnification, you do not need a huge prism to get good FOV an large exit pupil. The GLx 2x has a 12mm exit pupil and the whole thing weighs 11 ounces with the mount and everything. If I had to choose one optic for a lightweight AR, this would definitely be in the running.
The SLx micro-prismatics take that whole compact thing to another level. They are not quite as nice as the GLx, but they are notably smaller and lighter. What really shocked me was that since they are part of Primary Arms SLx line, my expectations were pretty low. Older SLx products I have seen did not exactly inspire me, but these are legitimately good.
And small. Did I mention small? I may have mentioned small. Well, they are small and lightweight.
Time will tell if they are robust, but they seem to be so far.
They barely have any effect of the handling of light weight ARs and remarkably enough, they are very easy to get behind. The eyepieces were designed with comfort in mind.
Optically, they are better than I expected. Now, I am not going to trade in my Elcan any time soon, but I am not going to buy another fixed power Elcan or Trijicon either. For what I need, these are plenty good enough and for the price of one Elcan I can have multiple ones. To be fair, I do plan to pick up a switch power 1x/4x Elcan, but that is a conversation for another day and there is a reason for my madness.
For ARs that are light, capable and easy to use, these new micro prisms are awesome. Now, the natural question is, if microprisms are so good, why would anyone want to buy a large prism scope? They do get pretty beefy as the magnification goes up. They offer a very wide and immersive FOV which has certain advantages. I'll talk about large prism scopes in a separate post.
Going back to micro-prisms, the other application for these is to assuage my paranoias. I really like to have backup optics pre-sighted in for most of my rifles. For conventional hunting rifles I usually use very lightweight SWFA Ultralight 2.5-10x32. For ARs. I think it will Primary Arms' micro-prisms. They are small, light and easy to pack. Unexpectedly, the integrated mount comes back to zero surprisingly well if I use a torque wrench.

To summarize all of this: not only do these punch above their price range in terms of overall performance, I can also have spares with minimal effort and without going broke. I'll have the videos up with some extra commentary soon. In the meantime, this was why they are among my recommendations.