This really has nothing to do with longevity.. but HOW ON EARTH CAN YOU LOOK AT IT ON FULL BRIGHTNESS????? lol
It's like looking at the sun! These new monitors are sooo bright. I thought my CD 2.0 was bright as heck when I got it, but now the LED backlit 2.2 i have it like burning a hole in my brain! lol. I keep it at half brightness just to not go blind half the time 🙂
On a happier note. I wouldn't worry about it. Like it has been said, it's not as much of an issue. Your monitor will be happy and bright and colorful for years to come, probably easily longer then you or the next owner have it 🙂
edit: I see you have a CD 2.0. Either way, my question still stands lol. I think I used that on full brightness maybe.. 2-3 times the whole time I had it. SO BRIGHT! 🙂