I had my first real night drive recently in the countryside with these lights and WOW. They are brighter than I expected, and the high beams especially light up the whole world in front of you. Installation was pretty easy thanks to the well thought out relay wiring. Make sure you take the time to aim these correctly, for optimal performance and so you don't blind oncoming drivers. Since these bulbs have a European beam pattern, I used the E-Code aiming guidelines from Daniel Stern Lighting (google this and go to the Aim article he wrote for guidance).
I also opted to get the clear H4 bulbs that are offered separately, rather than the blue tinted bulbs supplied with this kit. I have no interest in the "cool white" look on a classic car, and the standard clear bulbs are a very nice bright white, not even yellowish like the old dim lights.
Very happy with the kit overall, great value and performance for the price. I'd highly recommend this if you ever plan on driving your Cougar in the dark.