I've been using it for about 4 months on a project to build a new spectrometer for the radio telescope at Arecibo. Arecibo is the largest radio telescope in the world (305m!) in Puerto Rico. It has 10-times the collecting area of the second largest telescope in Effelsburg (maybe near you?).
The project is an embedded linux box that boots from a compact flash card. The root filesystem is only about 5MB. X wasn't reasonable for such a small embedded system, but libvncserver was perfect. On the console we run graphical diagnostics that write directly to the frame buffer. It was a simple matter to hook this direct-framebuffer application to libvncserver. This way we can easily view the diagnostics for the spectrometer from the control room (or anyplace else for that matter).