Seems I remember one of the other big reasons the change was made was because of the problems that used to creap up in the general illumination wiring harneses. I'm sure you've all seen the burned wiring that was frequent in the older games. Especially, the early solid state machines that used the #44 bulbs. Replacing with the #47 cut the current consumption for the GI almost in half in most machines.

I can attest that heat is definitely a factor also. I've changed quite a few pop-bumper caps with the tel-tale brown burn marks from over heating lamps. To a 'T', always pulled out #44's and installed #47 lamps to fix the problem.

G