I think you need to strike a certain balance: for longer stretches of wire and higher wattage AC will work better. What doesn't make sense is building tiny swit

I think you need to strike a certain balance: for longer stretches of wire and higher wattage AC will work better. What doesn't make sense is building tiny switching power supplies into every lightbulb. I was planning to use a power supply for every group of lights — e.g. one for the ceiling, one for under-cabinet lighting, etc. That way you don't have to run long stretches of wire with DC, and yet you don't have to build lots of tiny low-efficiency converters.