I've had both H1s and H4s and I can't say that there's that much difference. The H1s are more adjustable. They are also ridiculous $ now.
You can buy higher wattage bulbs and get a much brighter beam. I used to get 100W for the H1s. I think you can get 80/100W H4s Get the higher wattage bulbs and wire in a headlight relay - that will make a big difference.
Personally, I'm happy with both sets of my stock 55/60 wattage H4s.
A few random hints:
- Check the headlight alignment. Put the car on level ground and aim straight at a wall. The dark/light line should be at the same height as the lights. The transition from flat-to-the-left to angled-up-to-the-right should be directly in front of each light.
- Check the bulbs you have in there now. As they start to go, they develop a silvery film on the inside. That will block some of the light output - put in a new bulb.
- Put in a higher rated fuse for the headlights. The stock fuses can drop almost a volt across them, particular as they get old. Putting in a 25A will noticeably improve the brightness. (All you fellow EE's cover your ears
) Putting in extra headlight relays and thicker wiring will have the same effect.
- The H4s have a quarter-sized shield in front of the bulb. If you remove it, there will be more direct path light going out, as the expense of more glare above your headlight line for oncoming traffic...