I have Meprolight night sights on my AK's. They work well, but I would prefer the rear dots were smaller, as they tend to overwhelm and fuzz out at night. Ive actually removed the the Mepro rears and re installed the factory rear sights on two of my AK's, due to the "fuzz out" problem. The front sight is fine, and a nice clean dot. It also works well by itself with the factory rear sight.
While the large, square front post works great at closer ranges, it does tend to reduce the useful range of the gun to about 200 yards or less. I shoot more accurately at longer ranges with the stock front post. I had the same problem with my Springfield SOCOM and its fat front post.