If you already have an alternator (Bosch 35 amp or larger) then the current load associated with H4 bulbs is not going to be an issue. I am a fan of adding external relays to switch the headlights which provides a shorter electrical path between the battery and the headlight (less voltage drop / brighter lights) and reduces the load on the headlight switch. Switching to LED bulbs drops the headlight current significantly and probably negates the benefits associated with relay switched headlights. In order to get a proper beam pattern you will need to switch to an H4 lens assembly (Hella / Cibie / ...) to accept the H4 LED replacement. If you can get the correct lenses and good LED bulbs this may be a worthwhile conversion - if you are going to make use of it with a lot of night driving.
For the headlights, LEDs may have some advantage. For the other lights I remain underwhelmed. High lumen white LEDs are not white (i.e. not broad spectrum). White LEDs are actually a high power blue LED combined with some phosphor (that yellow stuff that you see in the center of the LED). The phosphor absorbs blue light and re emits it as yellow light. Your eye / brain is tricked into seeing the combination of blue and yellow as white. The problem is that there is no red light in the yellow / blue mix and when you put it behind a red filter (the tail light / brake light lens) the performance in terms of lumens can be underwhelming. The yellow turn signal is less affected; but, you still do not get the advertised lumens. If you search hard, you can find some true red and yellow higher lumen LEDs that will work; but, tend to be rather expensive. However, these tend to be as bright, not necessarily brighter than the standard incandescents.
If you are thinking about changing the dash warning lights to LEDs, do not change the charge indicator light for an alternator to a LED. The charge indicator light forms part of the field flashing circuit for the alternator. A LED will not flow enough current to successfully flash the alternator which will leave you with a non functioning alternator. You can bodge around this by installing a 100 ohm resistor in parallel with the LED which should provide the required flashing current to the alternator; but, why bother.
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