I've got an Autometer Digital Pyrometer in my old truck (90 F250) and I love it, I got used to the digital pyrometer (EDGE Juice with Attitude Display) in my 04 SD and I didn't like the analog in my old truck when I put it in there. The Digital one is nice because it has big digits and you can see your temp quickly without even looking off. Both mine seem very accurate and I like them better than the analog, but I do not care for a digital boost gauge.
In regards to the one you linked to, I think an old friend of mine had one just like that in an old turbo ricer deal, if I remember right he had to hit it every now and then to keep it working, but who knows, maybe the Chinese have perfected them by now that was at least 5 years ago.