It took me about half an hour to install. The installation is not impossible but you have to apply a lot of leverage.
First, the accuracy improved. I only tested it at about 45 yards and got smaller groups than before. Some 2-shot groups were as small as 0.4". Would be interesting to see what it does at 100.
I am pleased with that. I could never shoot such groups, they were considerably larger with open sights -- mostly because I never did get a clean sight picture.
Now the downside:
1) The Mojo sight is not adjustable. Once you sight it in at some range, that's it. You cannot go from 100 to 200 meters as with the original open sight. I knew that, and I didn't care because all you have to do is know the trajectory at 200 - and it is not an issue anyway. I like the fact that it is fixed.
It comes with a tiny Allen screw (not sure what it is, 1/32" maybe) to adjust the sight. You can however, count the number of
revolutions of the adjusting screw. 1 full turn means 4 inches at 100 yards for drop and 3.5" for windage. But it is not quick and you need the tool, which is tiny, and can get lost very easily.
2) While it self-evidently results in better accuracy, it is still not as good as a real peep sight. That is not a problem, 2MOA from AK is outstanding. I haven't yet tested it at 100 or 200 but thus far it makes me optimistic.
3) The biggest drawback -- while you gain accuracy (in my experience anyway), it is slower. The sight picture is slower to acquire. The pistol sight on AK is quicker. It is not much slower, but some fraction of a second. If I were to guess, maybe 1/5 to 1/4 second. Don't know if practice can overcome that.
My overall impression: I recommend it. Especially if you feel that you are not getting the accuracy potential of the AK (that's how I felt) and turned out I was right.
All things considered, I don't feel that Mojo is the best solution, but it is the ideal compromise. A really good sight would
be a peep sight a la AR-15, but it is not going to work on the AK well. You have to modify the receiver cover, and then it won't come off easily, and be expensive. So while not the best, it does indeed work better than the stock one, which is useless in my opinion.