I have used a Steiner M332. The glass is very clear, but I could see that it is not for everyone being that it is a fixed 3x scope. Once Trijicon's patent on the prism scope expired, there are a ton of lower cost options of varying quality. While they may use the same or similar tube, giving a similar appearance, just like an afterschool special, "it's what's inside that counts" in terms of glass quality, scope adjustments, mounts, holding zero, etc.
The fixed prism scope is not good at short distances, like 0-25yds, which is why it's usually piggybacked with a micro red dot. Typically, they need to be mounted with a shorter eye relief than a typical scope. If you use a prism with a harder recoiling cartridge (like a 308 Win), you won't get a crescent eyebrow scar due to the rubber coated eyepiece, but it is apt to push your shooting glasses into your face.
There's no way to use BUIS through the prism scope, but offset BUIS would be complementary. A person could take off the prism to flip up their BUIS also.
It slots better at 50-100yds - up to about 300yds since you can see a little better than an RDS. Obviously, shooting 300yds at 3x is equivalent to irons or a 1x dot at 100yds. Most people don't have trouble with that as long as the target is big enough. It's not ideal for uber-precise shooting at distance, but most people considering a fixed 3x already know that. I used 5" to 6" targets at 100yds and that was ideal IMO for 3x. I could see 223 Rem bullet holes at 100yds with the M332. I needed a higher magnification to see the grouping, but I was pleasantly surprised that I could see the holes at 3x.
Some may make the argument, "If I already have a 1x RDS, why do I need 3x magnification?" The answer is that you don't. RDS's are more plentiful than they have ever been and the popularity of the 1-6 scope has put a damper on prism scope sales. The prism scope, in a way, combines a RDS with a magnifier in a smaller package, without the ability to switch between 1x and 3x. It is a product of compromise.
Knowing their limitations, prism scopes are a simple solution for 50yds to 300yds+. They will never be as popular as RDS's, but if you can live with the limitations, a prism sight may be for you.