I used Philips Xtreme for the first year on my 800, much brighter than standard and well worth the £20 I paid.
However, after seeing HID's on other bikes, I then switched to the 50W HID units. You have to see the difference to believe it - instant daylight and cars move out of my way all day/night. But there again, they are £150 for a decent pair.
If you can afford it, HID's. If you can't, Philips.