Car Nav Update

Today I updated the nav firmware in my car using some very special SD cards, and installed new maps (K0260 and Western Europe 2015). It was a little tense and complicated, and I was fearful that I might brick the head unit, but all went well and the maps are installed and operational. Only slight frustration is that Audi do not appear to publish a change-log, so I'm not sure what is different in 6yrs of firmware updates. Any clues?