Given the shrinking price of 40" TVs many companies use them instead of FLDs and just replace the set when it dies. If you don't need the features or extreme brighness it works fine.
I use two older TVs as a 24/7 window display and have not had to replace them often.
If you have to pump up the brightness they probably wouldn't last as long. I don't have mine jacked up. Get TVs with wide viewing angles. That makes the display easier to see off axis.