Have just installed a set of Silver Star headlamps and they are noticibly whiter than the XtraVision lamps they replaced. There is a downside though, they do not seem to last very long. According to Sylvania the XtraVision (also 55/65 watt) is rated for 850 hours before needing replacement which is quite a while for most people.

The SiverStar OTOH is only rated for a life of 100 hours or "We estimate the SilverStar halogen lights to have a life span of up to one year under average driving conditions."
http://www.sylvania.com/auto/sstar_faq.htm

Has anyone been using a set for over a year ? What happens ?

Think I will put off replacing the XtraVisions in my other cars.

had 'em in my parents buick for a year and a half, my car for a year, and my truck for eight months now and i have not had a single problem

I have them in my parents Montana for a few months, my Bonneville for about 5-6 months, and most of all in my Malibu.

The reason I say most of all my Malibu is that I drive over 5,000kms a month and have had them in since October. I drive an average about 20-30 hours a week so I am up somewhere between 200 and 300 hours and they have not burnt out yet.

I like them allot and they really helped me out at night a few times while driving down some pretty dark roads.

In today'* Orlando sentinel there was a Pep Boys coupon for SilverStar headlamp bulbs, two pack for $29.95. Such a deal.