The adjusters are either broken or they're not. It matters not if HID or Halogen - in fact Halogen may be more prone, due to extra heat put through them.
Once they are broken, manually adjusting won't really help (in fact you can't really).
Fitting the ali adjusters is dead easy, if a tad fiddly. You just need to be prepared to catch the hot sealant, to stop it going onto the chromed reflectors, as you'll never remove it without damaging the delicate chrome (note - Boots nail varnish remover seems best if you do, but does cause minor discolouration). Additionally, grease the thread, as we all know that mild steel into ali corrodes bad
Its only the horizontal adjusters that fail normally, and these are the ones that you can get ali replacements for. When they fail, it affects the height, and the whole moving part of the headlight assembly becomes loose at the bottom.