I think of these items like wearing items, sort of like chains or cables. They have a limited life span. But for 6 or 7 bucks, it's pretty painless.
But the last ones lasted for 7-8 years. Not bad, but they don't make them anymore. I'd prefer LCD displays since I ride almost exclusively during daylight hours.
The handlebar mount really makes it practical. There can be problems finding a good place to mount them.
Here's the one on the Norton.
Hard to photograph the display
PS the oven is for powder coating