I ordered 4Crawler's kit for my '85 Toyota pickup, and that alone was impressive with the stock headlights. I also ordered Hella Vision Plus H4 housings and used the bulbs that came with them. They helped even more, but I'd have to say the harness was the biggest improvement. My lights don't look dim and yellow on the road anymore.

I liked the setup so much I ordered a second harness to use on my '90 4Runner. This time I'm going to hold off ordering more Hella H4 housings/bulbs until I see the improvement with just the harness alone.