I just installed some IPF housings with IPF FatBoy bulbs the other day. I previously had sealed beam Sylvania SilverStars installed. I believe they have the same light output as stock, except the light is a much cleaner white.
Anyway, the 'data' part of this post is that I used a light meter to compare light output of the lamps and also aftermarket wiring harness (suvlights.com) performance.
Here's what I found:
Sealed beam SilverStars = 4,000 candlepower
IPF H4 w/FatBoy = 16,000 candlepower
IPF H4 w/FatBoy and wiring harness = 22,000 candlepower
Overall, I am very very very happy with them. The beam pattern is terrific in low-beam and I love how the signs on the side of the road are now very visible. The high beams remind me of a spotlight. Very very nice...
Oman, if you read this (and I'm sure you will
), see if you can get access to a light meter and measure your HID's. I know they'll be brighter, but I'm just curious as to how much brighter.