I voted single ended, not because it is better but because it is my preference. I feel I get better spread out of single ended setups, primarily because I can be more selective about reflectors. I also love to run 400w SE Radiums on an HQI ballast. Amazing color and growth. I currently have a DE 250w fixture over my 90g and have to say that I have been impressed with the output of the 250w DE bulbs in comparison to my other 250w single ended bulbs not on HQI ballasts.