All HID systems are self levelling. It's just that self levelling only works in 90% of the cases. Pothole? Doesn't work. Going over a gradually changing slope? Doesn't work. And perhaps the worst part: car becomes ~10 years old and self-levelling system has experienced sensor failure? You're officially a safety hazard.
And it only takes that one second to spoil your night vision for the next two-three minutes. In a city, it may not be a problem, but when you're driving through the forests of northern Sweden and you really want your night vision at its best to spot any moose crossing the road, it's bloody dangerous to have someone's low-beam HID blind you.
IMO, HID should be disallowed for all low beams, and should be freely available for all high beams. This would solve all the problems, except new cars would not look as "cool" as they do today.