I am currently using both the Ushio Super HPS and the Digilux. They are both on Lumatek 430 ballasts. The Ushio is on a Cooltube and the Digilux is on an Adjust-a wing reflector w/ super spreader.
IMO, the Ushio is the better lamp, even though the Digi has the better reflector and it is closer to the plants. It seems to perform better especially in veg.
EM