Gee, thats interesting, as we have some bulbs which have lasted for so long that they get dirty from dust. I forget to dust them when Im doing housework, and if our wood stove is being used a lot the livingroom bulbs do get that fine gray dust on them.
From what Ive observed, the CFL bulbs burn out way way quicker than the old ones.
Yes, I have 2 boxes of various sizes, mostly 100 and 75s and a few 3way ones in the cellar.
The bulb in our new garden shed, has lasted for years and years. And our outside spotlights, seem to go for ever.
So I am sticking with the old bulbs until maybe someday there will be a newer and better technology. LED bulbs will probably be the way to go.
http://eartheasy.com/live_led_bulbs_comparison.html#d
Just spotted this site, has some interesting stuff. Nice charts too,,,,,I love the first paragraph, here is the quote,,,,,,,,
"LED light bulbs will eventually be what we use to replace incandescent bulbs – CFLs are a temporary solution to energy-efficient lighting. The reason LEDs have not yet displaced CFLs from the market are twofold: the first generation LED bulbs had a narrow and focused light beam, and the cost of the LED bulbs was too high."