I have both lights, the Maxfire and the G2.
I have taken an extra Surefire P61 lamp assembly and put in the Brinkman Maxfire after removing the stock reflector and bulb assembly.
The G2 and the Maxfire both now have the same output, there is no difference.
As for the rest of the light, I see little advantage either way.
G2 + P61 = $61.00
Maxfire + P61 = $44.00
Not much difference but not much difference in the lights either. Might as well save a few bucks.