They are not overdriven, so its going to be an electronic ballast pushing normal wattage.
As far as refelctors are concerned, they are going to be similar to the ones icecap(aquactinic) and sunlight supply sell. Theres really not that much difference between the different single bulb parabaloc t5 reflectors.
As far as cooling is concerned, aquactinic and ATI make the only activley cooled hoods. Active cooling will increase your par and extend bulb life. The Ati may or may not have "more" then the aquactinics hood, but again it will not be a huge difference.
So in conclusion, you pay about 1000 more for a nicer case and 2 more bulbs. There maye be up to a 5% difference between the two, but really its going to be negligable. Especially 3 months after youve started running either unit and theyve both lost 20% par =P