The latest drivers on the Sager support site are only a month old for Vista and five months old for XP. I think that's pretty recent so you might as well install those since they're supported. I'm personally using older drivers and I don't recommend updating from the supported ones unless you start having specific problems with your video drivers which you shouldn't. Specific problems would be something like not having support for a late release game or having a known bug that has been fixed in a later driver release.
People think they always need the latest video drivers but it's not always the case. If it ain't broke, don't fix it.