guardian452 wrote:
So you have both huge inefficiencies and mercury hazards which could be avoided, not to mention cri and flicker would be drastically improved.
Modern T8 tubes and ballasts can actually be more efficient than off the shelf 120VAC driven LED bulbs, if not at least usually on par:
https://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2
Additionally LEDs typically don't have good color rendition, although they do cheat on their CRI measurements to get higher index numbers. A somewhat lengthy explanation here (from cinema, where they spend lots of money on LEDs but don't always get the results they want vs. tungsten or kino flos, etc.):
http://www.screenlightandgrip.com/html/LED_Lights.html
Generally speaking, if you do have good color rendition, you trade off for it in terms of efficiency. For example, low pressure sodium lamps (practically speaking, in terms of available products) beat LEDs by miles for luminous efficiency. But they're only giving you one wavelength. Tungsten gives the best color rendition as the closest to a true blackbody radiator, but of course isn't very efficient.
Of course if you have old fluorescents with old ballasts, and old phosphors, a modern LED bulb will probably be better. Certainly the sickly green lights of the 90s were nothing to write about. However, after moving to all LED lighting at home, I am in the process of getting rid of it all and going back to T8 tubes. Between poor light quality (color rendition and point light sources) and dying bulbs from manufacturers (mostly in the shoddy "power supply" sections rather than the actual LEDs), it really just didn't live up to the hype.