acwats, standard (factory fit) Xenons are considerably better than conventional halogens.
The colour output of the light is very different to halogens, so much so, that it gives considerably greater illumination of white lines (on the road surface
), reflective road signs, the scotchlite reflective piping found on trainers and kids rucksacs (and the BiB in unmarked cop cars), and even the reflective "battenburg" markings on emergency services vehicles - very handy for advanced warnings of cop cars hiding in hedges . . . whoops, I meant approaching ambulances
so you can "modify" your driving near said vehicles.
They also have automatic level control, which standard halogens (and retro fit Xenons) don't have. The most crucial safety advantage here, to the driver, is under hard braking - on halogens, the cut-off of the dipped beam reduces dramatically as the nose dips and the rear end rises - on Xenons, the beam distance remains constant. That same advantave is also offered to on-coming cars under acceleration - instead of illuminating the stars (and on-coming drivers), like halogens would, Xenons automatically "lower" the beam under acceleration.
IMHO, Xenons are a valid safety improvement, to both the driver and other road users. Similar logic could be used for say airbags or seat belts - until you have a crash, they are pretty much un-needed! At least Xenons help to see where you are going much better!
Regarding your E-class, they were a very poor example of Xenons, because MB were initally adamant about NOT using the elipsoidal, projector type headlamps, and relied on their "traditional" open reflector type headlamp units. These gave very poor control and definition to the Xenon beam, and as such, were not the best advert for Xenons. They too have now finally bit the bullet and converted to projector headlamps for Xenons.
