I was surprised how short of life i got from incandescent bulbs in a WPC89 game (drac). Within 15 months of home use, not turned all that much really, I had many GI blackening and burning out. Drac blinks the GI a lot. Not sure if that causes added stress compared to a game that just leaves the lamp on all the time. I just put frosted warm white LEDs in it after a bunch burned out before the 2 year mark of light home use. For an operator where the game is on all day it would be a nightmare to have all the bulbs burn out that fast.
There as been speculation the new made incandescent lamps have crap life compared to the old manufactured ones. Bulbs used where the made in china ones that come in the white mostly unbranded box of 100pcs with the cardboard crossing separators. Not sure if Eiko ones are any better.