This is a much higher class and already not just a compass but an optical device. Its major advantage is the precisely aligned collimating eyepiece. It's principle is similar to the red dot gun sight. Regardless of your head position if you see the marker it will be collinear with the compass major axis. What's very effectively removing another source of human error (alligning the front and back sights). Ideal for precise target sighting. Definitely a nice thing. I had experience with the similar type Sight Master (iirc), works great but extremely sensitive, a tripod mount would be a great addition. However, they are obviously having a limited use in the mountains, as you cannot extend a collimated sight far from the dial (optics limitation), nor tilt it far enough.

By the way, I love my scuba diving Suunto compass. As in a whatever awkward position you are - it will show you the horizon level and the azimuth (it has a weighted ball like dial). But surely it's way too enormous for a land use.