The problem being you can only use LEDs for the indicators, brakes, and side lights, and of course the dash lights. So that's 4x5W, 2x21W for the indicators, 2x21W for the brakes, and maybe 3x5W for the dash, making a total of 119W, most of which is intermittant anyway. Compared to the 2x55W for the headlights whenever it's dark, not including full beam with quad lights!
There is certainly at least some of a power saving to be had by using LEDs though, and one day I will probably buy some. Would have been nice for thelocal place that sells them to have more of a clue about their legality than "I assume they must be, cause we sell them".