You are not able to compare... facelift and pre-facelift setup is to different.
I have a suspicion that the under lying reason why self leveling and washers are mandatory is because its something the safety people have been pushing for for quite some time......and HID's was a convenient technology to introduce it on!
Whilst different, I wouldn't say drastically different to have a huge difference - similar shaped lens, same bulbs I believe (and being projector, no reflectors to make a noticible difference) :-/
Problem with levelling, on a halogen car, if you look directly into the light, its pretty bright. Do same on a HID, and its like looking into a camera flash (similar tech I guess?), and you'll be blinded for a second or 2 - anyone who's had a gatso go off in their face at night with nothing around will know exactly what I mean. The levelling helps keep the lights at the right angle should it be loaded up a bit, and (on new cars) fast enough to mostly deal with bumps.
As to washers - we all know how bad our halogens are at the moment with this 'november' type grim being kicked up from the tarmac. It affects them, and light output goes down significantly. With HIDs, no idea why, but light output goes down to what I would class dangerous levels very quickly, to the point that I am washing the lights rather than the windscreen. I have never had to clean headlights so much as I've had to with the 2 HID based cars I've owned - I'd say after a motorway trip this time of year, the lights are on par with pre 98 Omegas....