I can't imagine the same current would be drawn to power the 600 watt bulb as the 1000 watt. The excess 400 watts not sent to the 600 bulb would have to be dissipated in the ballast making it much hotter. No advantage as far as cost of electricity either. Being digital I would think the pulse width of the power train sent to the bulb would be narrowed so the juice would be off longer than it was on per second so that less energy would be available but none wasted.I'm pretty sure the lumatek dimmables draw the same ammount of current, even when "dimmed". (Still draws 1000w even at 50% output)
Can somebody with an ammeter confirm/deny?