Also, Lumens per watt can vary quite significantly from one to another.
Agreed. Not only in the actual usage, but also in the supposed "equivalence".
Get to know your Lumens boys and girls, because watts mean nothing anymore and we need
a new yard stick. As far as equivalence goes, 60 watts = 800ish Lumens, plus or minus any
fudge factor the manufacturer thinks they can get away with.
Oh, and years of life... Always calculated at 3 hours per day, or some silly very short period of time.
Still, I've got only a few more trips up the ladder because I don't expect any of the LEDs to fail in my remaining life time.