In my current 2x4 run I have two Spider Farms SP1000 and in between those two lights I have an Autocob. It's a 3 plant grow. Both are very nice lights. The Autocob is small, easy to move around, only .49 amp draw and noiseless, as there is no fan.
www.cobshop.net.
My preference is always a good light spread, so two lights of less wattage, I'll take over one light of higher wattage.