You are more than welcome. I am a lighting nerd for sure.
I am in an area that has a lot of growing and technical knowledge, so I get to see and use a tons of things not all the county has access to easily. Plus once I got in to LED's it made me have to understand every aspect of all lighting sources and plant growth/responses.
Prodigalsun...
The digital ballast are more efficient at converting power to light. In the ballast test I posted there is only one magnetic ballast(old school heavy), and it shows that it puts out less light than even the bottom end digitals. But bulbs still make a differrnce using magnetic ballast too.
Some will even argue that a digital 600w is as good as a magnetic 1000w. I personally wouldn't agree but it is probably close.