The usual counterargument is: voltage drop can become a problem. Trying to use one big power supply and use DC as your only distribution mechanism probably isn'

The usual counterargument is: voltage drop can become a problem. Trying to use one big power supply and use DC as your only distribution mechanism probably isn't a good idea. But choosing a DC system for part of the house can make a lot of sense. For one residential new construction room, it can be practical to have one shared power supply rather than one per LED. Say you have a 12 V, 5 A DC power supply. Using a star wiring topology, this can serve 10 lights (at 500 mA) fine with 16 AWG.