Wow, do they really explain a lot of the story. The new perspective it gave on the story was very interesting. Especially when you collect the 30th audio log, and the corrupt police officer hired by Kinsler tries to kill you.
I really suggest listening to all the audio logs if you haven't already. They are very interesting.
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Audio logs worked well with the scenario and story of ODST and with the whole "city at night" feel/theme. I would not want them in other Halo games because I feel that they wouldn't work as well with the theme in upcoming games.