Good glass and they are durable and accurate. I prefer other brands because of some features on Nikons that I just don't care for. They tend to be heavier and longer than other brands with much shorter eye relief.
They also tend to have a "tunnel vision" effect when looking through them. Imagine looking through a cardboard tube that a roll of paper towels came on. There is a rather large black ring around the edge of the view through Nikons where some other brands only have a thin black line that is barely noticeable. This combined with the shorter eye relief make it harder to get behind and get a clear view especially if you have to do it fast. Not as noticeable shooting off a bench where you have lots of time to set up the shot.
In the same price range I much prefer Redfield Revolution, Burris FF-II, or Leupold VX-1.