there's also the sylvania xtra-vision in H1... these are really the Euro OSRAM Silverstars repackaged for sale on this side of the Atlantic. it's about $20 for a 2 pack at Kragen/Schucks/Checker, you can try the other stores too. there's no need to mail order these anymore.
the OSRAM Silverstars are equivalent to the +50 style bulbs out there including the philips. it's a clear bulb with a different mixture of gas to get a brighter burn. not superwhite, like the Sylvania Silverstars you're asking about.
as far burn outs, these aren't the same as the Sylvania ones. i've had my set in for well over a year and they're still running. at the end of the day, how long your bulbs last depends on usage and to lesser degrees installation and the manufacture of the bulb.
anyhow, scroll down and look for the OSRAM Silverstar thread and decide for yourself.