Users with large music libraries (>20,000 songs) sometimes notice that VoxCommando takes longer to load once they have generated the xml for their music libraries.
For more information on why this is, and options for reducing load time see: http://voxcommando.com/mediawiki/index.php?title=Large_music_libraries
Most of this applies whether you are using JRiver, XBMC, MediaMonkey, iTunes.