Hi Chris,
I know you recommended the 250 W Luxcore for 250 HQI but since I felt that they did not entirely produce the same output as my old M80 ballast I purchased the 400 W because I needed a third ballast. I had bought 2 250 W before. I have now run it and I think that the light output from the 400 W on setting 300 W is brighter than the Superlumens setting on the 250 W. I don't have any instruments, just by looking. Am I imagining this or is the larger ballast actually cranking out more power?
I would be also interested in what the actual power draw is between the ballasts on these settings. I would imagine you have access to such specs.
Tapio