i ran the franken-boards for a couple of days hooked to the kill-a-watt meter. it pulls 308 watts, 117 volts, and 4.2 amps from the wall. one buck was set to 2.0 amps and 44.5 volts, the other was 3.5 amps at 42.4 volts. if i did the math right (which i had checked by an electrical engineer) thats over 75% efficient, with hobby shop parts.
both lights will run higher, which should = higher efficiency, so i'm pretty happy. we've since found meanwell power supplies at just a couple of dollars more, and they ought to be at least 5% more efficient, so when i build the 4 of these i intend to flower under, thats what i plan to go with, whats you've seen so far, with the power supplies swapped out for meanwells