Of course we have to be thankful for small mercies since TVNZ's HD offerings are laughable. I was watching snippets of Twilight last night on TV2 and the AAC audio is just lousy (even with DPL IIX Movie processing) in terms of effects, direction etc. compared with standard Dolby Digital.
Many of the Twilight scenes make extensive use of the LFE channel which of course does not exist on AAC stereo.