In case anyone else needs encouraging to do this - I was in a similar position to the OP - pretty feeble headlights. So having checked out various recommendations I went for a Landreiziger loom, and crystal bowl headlights/Osram nightbreaker bulbs.
Went to fit the headlights today, but the retaining rim and all the screws were rusted and seized. I hadn't bothered to get new ones, so the old lamps have had to stay in until I can get new ones ordered.
But I went on to fit the loom. Simplicity itself. I connected the positive feed to the alternator; an earth on the wing, where the relays themselves were mounted; connected to one of the old headlamp H4 plugs; and then just connected to the headlamps.
Using the exact same bulbs and bowls, what a difference! I was amazed. Bright, white light were there used to be feeble and yellow. On dipped beam, I can now see much better particularly with oncoming traffic. I was hoping for a noticeable improvement, but the difference was much more than I expected.
About 4 or 5 years ago I fitted a pair of Hella driving lamps - 100w bulbs, wired to the main beam. This was before I'd learnt about the issue of a poor wiring loom to the headlights. On the test run tonight, the orginal lights were so bright the Hellas only made a marginal difference.
Seriously worthwhile improvement - and an easy thing to do.