I've used the Xtreme White Plus for a number of years - noticeably better than standard, even in headlights that are poor in design and about 3-candlepower with standard bulbs.
IIRC they are E-marked and therefore legal for the road, and they also seem to last for ages - it's so long ago that I can't remember when I put the set in the missus' car, but they're still going strong. (Touches wood.)
Just make sure that you buy from a legitimate seller and not some random ebay person based in China... lol