We first saw the Shearwater NERD (Near Eye Remote Display) during field trials at Divetech's Inner Space last year, and were pretty impressed.
What makes the NERD attractive to rebreather divers is the sheer amount of information it conveys in an easy to read format. Instead of a basic HUD (head up display) that shows a series of different coloured LED lights (primarily green or red) that flash or are static, you get the useful data you really want. It seems as though the data is displayed on a 32 inch TV screen a mere 12 inches away from your eye. Crucially the display is unobtrusive so it virtually disappears when you look straight ahead.
The Shearwater NERD displays the same information as the Petrel diving computer with key warnings displayed in a different colour.