Phantoms are the best. They have all the options of a lumatek, plus dimmable percentages of bulbs. I just wish they made a "dual 600" phantom. Until then I will always stock Lumatek right along side it.
The down sides of the others:
Galaxy: chinese circuits and resistors. capacitors are filled with inferior oils. Pro: the "1500"
Nextgen: The fans blow dust onto the circuit board and can fail overtime. Pro "180 ft lamp distance"
Quantum: They are bulky and noisy and have fans and put off more heat than the others. Pro: "build quality"
Lumateks: Better every year but still get returned but they get returned more because they sell more. Pro: "dual 600, dimmable 400, 1,000w 240 models"