How useful is the 4 MOA dot past 100 yards?
My Aimpoint with a 4moa dot works fine at 200 and I'm sure 300 wouldnt be an issue.
I guess the irons on an AK aren't so great past 100 yards anyway.
The stock AK sights arent bad, and 300 yards with them is a very realistic expectation. At 200 yards you can expect this. (and these are somewhat canted to boot)
I recently put a set of Meprolight three dot night sights on a couple of my AK's. These are bigger than the stock sights and do reduce the effective range to 200 yards and in. Like the oversize sights on the SOCOM's, they work great for close up fast shooting, but tend to be a chore for longer range precision stuff.
Personally, I like the Aimpoint/Ultimak combo the best so far. Its a very solid mount, with a combat tested sight that is rugged and will hold up to abuse. You still get the cowitness, and everything is up front and out of the way. You can also still use a windage adjustable rear sight, or any sight combination you want with it too. I have the older M2's and the batteries are 24/7 on with one change a year. You can also use the Aimpoints with the front cover closed, which allows you to set the dot brightness so you can go from dark to light and back without fiddling with the brightness. Also eliminates the need for those annoying killflash's.
Not knocking LaRues set up there, it looks a lot better than most of the others, and the mounts I've had from them are first rate, so I'm sure the quality is there. I'd have to wait and see how things hold up and if the sight itself is durable and will take abuse. It looks somewhat fragile. I dont like the fact that your limited to that rear sight(unless they offer an adjustable too), and I also prefer the dots to be as far forward as you can get them, and they have it going the wrong direction.