I have had them awhile, before 2006 I think, and the reason I didn't use them was brightness. They are dimmer in the middle, and it "appears" the phosphors have a brownish tint to it. I expect this is an illusion. I see Home Depot has them also, but made in Holland. Are they any beter quality? The 20 watt one acts ugly on the first start, often it will go out after being on 5 or more seconds making the starter work hard on the next start. We shall see how long this lasts as the daytime unattended kitchen light. These F15 bulbs ( back on subject) are in my cheapo dual 15 watt desk lamp. Holding the preheat button down BARELY glows the ends, and I leave this lamp on 24/7.  I may get brave to see if I can take the bottom off and put in some GOOD ballasts, though the previous GE and Sylvania worked OK for a good while.  The Sylvania on the good ballasted lamp wanted to swirl and sometimes go out.... but once it got left on 24/7 it started to behave. 

Powell

Maybe you can try the GE Natural Sunshine/Chroma 50 F15T8s from Hungary? The Philips F15T8s from Holland seem to be pretty good too.

I have some of them in use here at the house. I will see how long these last. The reason I brought those to the radio station was when they were on (the Phillips) it made loud racket in the AM radio and I work for an AM radio station. I may get some of the Holland made ones to see if they are any different. I would rather have Duro Test 15 watt Optima 50 bulbs but those aren't made any more.


Powell