However, jumping over to the other side of the fence for a moment, a potential safety advantage of Xenon lights may be:

Lastly xenon headlights have a similar lifespan to normal headlights (about 1500 hours) but do not fail suddenly. Instead they gradually go dim as the gases properties weaken.

(From this site.)

This is in addition to their lower power consumption for a given light output compared to Halogen lights.