> But of course something like that is more expensive...

More expensive than an inefficient unit, but it should still be a lot cheaper than 120 separate units, right?

And I expect one big fat unit to do a better job of smoothing out voltage and avoiding flicker than a bunch of single-light units. Especially because the output capacitors are sized for the entire system, but you'll rarely have all the lights on at the same time.

Though for efficiency I'd think you'd want 48v and not 12v.