T8 benefits

["Hopkins, Samuel" <Samuel.Hopkins at marconi_com>]

Where do the benefits of T8 lighting come from, the ballast or the bulb? 

For instance:

T8's are brighter because the phosphor doesn't get a chance to dim as much
because of the 20,000 htz cycle (opposed to T12 magnetic ballast's 60 htz) 

T8's decrease only to 90% inital lumens whereas T12 goes down down down....

T8's last 20,000+ hours. Since the real lumens stay at 90% of the initial
lumens you'll actually get 20,000 hours of use instead of T12's 6 months.

T8's are made with newer tri-phosphor coatings whereas T12 isn't - does that
matter? 

So what gives these beneifts, the bulb or the ballast? Are the benefits
really from the electronic ballast regardless of the tube type? 

If you overdrive a T12 bulb with a T8 ballast will you get the same benefits
of a "T8 bulb setup?" My problem is that T8 bulbs are in  short supply where
I live for the different spectrums. My choices are (better sit down this is
pretty long): 3000k 72CRI or 4100k 82CRI. =) I can mailorder but if I can
get the same benefits with a T12 bulb I'll stick with them.

I overdrove a T8 light X4 with a T8 ballast and compared it to a 8 month old
abused T12 bulb powered by the same ballast (also overdriven X4) and the T12
bulb looked brighter. The T8 looked bright as heck on the ends but dim in
the middle.

Sam